I'm most interested in Mox Amber in your list. How often has that not tapped for anything? Even with Jaya using useless and/or situational cards, I try and avoid those where I can. Does having three Welder effects keep that useful even when you're not tapping for mana (ignoring that one of those effects turns it on).
The other one I'd be curious about is Command Beacon. Jaya's activated abilities are pretty mana hungry, so going down a land to recast more cheaply doesn't seem quite as useful here as in other lists until you get up to the third cast or so. Nonbasic lands are also one of the places I've had the most trouble fitting everything that I'd like to run, so those slots are kind of precious to me.
On the whole I like it a lot. It looks like there's a lot of explosive potential with the spell copying and the burn spells, which is a really fun place to be late in the game.For my list post-MH1, I swapped Magma Phoenix→Tectonic Reformation. I've found that I usually have enough to do that I don't recur the Phoenix all that often. There's a pretty good chance it comes back in for either Jaya Ballard or Dire Fleet Daredevil at some point - I like having the option to recur, even if I don't use it all that often, and I'm feeling a little light on fliers. I might also look into some of the other phoenix and dragons that I've either passed on before or cut from the deck in the past. I've found them really useful for carrying equipment and chipping in some damage to help supplement the burn plan.
I don't have a cut in mind for Prismatic Vista yet. Mountain is an option, because it's not appreciably dropping the basic land count in terms of cards off the top and it's rare for me to actually get all of my basics out of the deck. I haven't wanted to go below 20 in the past, which has me a little hesitant. I also kind of want to fit the Wastes back in the deck once Vista is in, possibly Endbringer as well. That would give me thirteen colorless sources, which is enough to play Endbringer on curve 85% of the time and activate the card draw a turn later 60% of the time. The odds obviously get quite a bit better as the game goes on too. With the chip damage and combat manipulation options on top of that, it seems like it's probably a good fit. The downside being that I'd have to find even more cuts to make that fit.
I'm thinking of trying to do a large scale primer update when MTGNexus opens up. The existing formatting is already a little broken from the Curse acquisition (many years ago) and I never got around to fixing it. The new site is supposed to have very similar BBCode with expanded options, so it's likely some of it will break further and there will be opportunities to pretty it up a bit. It also needs some content reworking, to better reflect some of the new card options and changing thoughts on the old ones. It's tough to promise anything or give a timeline on it because of how much work needs to be done, but it's certainly time to attempt it.
Field of the Dead is a neat utility land. Landfall - make a zombie is a decent ability on a land and the condition is achievable in a lot more decks than something like Valakut, the Molten Pinnacle or Emeria, the Sky Ruin. I also appreciate that it rewards you for running some snow basics and that those can help turn it on in basic heavy lists. ETB tapped is a downside and colorless only hurts, but I appreciate that it opens it up to every deck in the format. I like this a lot overall.
Golos, Tireless Pilgrim is good. I'm kind of burnt out on 5C legendaries that are clearly aimed at EDH right now. This is number 6 in about the last year, including 3 in the last set alone.
Cryptic Caves is a decent pickup. I'd still value the horizon lands higher because colors matter, but giving every deck including monocolored access to the effect is nice. This feels like the last land added a lot of the time. All of that aside from obvious applications in land decks like Windgrace or Titania.
I have to say that the new owner barely having a functional website doesn't seem like a good sign. I'm much more interested in seeing what Airi and cryo are coming up with.
The mythic one is probably borderline most of the time. The floor is either a glacially slow clock, overcosted small sweeper, or bad removal spell. The high loyalty and the uptick for emblem are admittedly great and probably the most inevitable clock we've ever seen - aside from a non-countering counterspell or a stifle effect, there's going to be at least one emblem on each opponent. If you can protect it long enough to get multiple emblems and expect the gmae to go for at least a few more turns, it's reasonable. 5-7 damage to each opponent for 6 mana isn't a good rate, but it's not horrible and the inevitability makes it better. In most metas I've been a part of, it's probably pretty mediocre.
All of that said, I love the card and I'm jamming it into more decks than I should. It reminds me a lot of Obsidian Fireheart, which is another card I like a lot and play more than the power dictates. Small, inevitable damage is a lot of fun.
I appreciate that people are still reading it. That's the reason to do it, so thanks to everyone who keeps coming back for the discussion.
I've only seen Frenzy a couple times, but I've liked it a lot. It's usually drawn a removal spell pretty quickly so I haven't really felt stuck with cards in hand. Accumulating cards in hand while still progressing a board state has been nice. I'm still waiting for the Frenzy play where I hit a long string of lands or something, because it's bound to happen sooner or later. Reformation also plays really nicely with it, because every time you hit a land you basically get to just pay R to move past it, and I'd like to see that interaction happen at least once. Frenzy's slot in the deck is obviously not set in stone, but I've really liked how it plays so far.
Engineer is the one I'm least sure about. The Welder-lite ability is OK but won't grab the things I most want to weld, and I'm not sure how well I can take advantage of the entomb. I like the card a lot, but I haven't gone deep to see if this deck supports it as built.
We also just got the first few M20 spoilers, and they're all Chandra. Chandra, Novice Pyromancer is clearly for a different deck and that's OK. Chandra, Acolyte of Flame is getting closer to good here. I'm not heavy enough on red walkers or cheap instants and sorceries (even if another way to flashback Comet Storm is usually welcome), so that's unlikely to make the cut either. Chandra, Awakened Inferno is in the spoiler below. I love the +2 so much. I don't think it's even that good in a 40 life format, but I love it. I'll happily drop this and spend a bunch of resources trying to protect it so I can stack those emblems. It reminds me a lot of Obsidian Fireheart, which is a card I try and run more often than I probably should. I'll probably try and run both of them simultaneously at some point after Chandra drops.
As an attempt at slightly less biased evaluation, the cons are that 6 CMC is a lot and the damage is glacially slow if you can't stack emblems. The pro is that uncounterable means that you're almost always getting some return on investment, barring a handful of counters that don't actually counter or a stifle effect on the activation. There are very few things more inevitable than an emblem under opponent control as well, which is appealing for a control deck. It also starts at 6, immediately ticks to 8, and the emblem ability is a plus, meaning anyone trying to stop it via creature combat probably has to commit at least a couple creatures. It's reasonable to think that you'll be able to get a second emblem some amount of the time, which makes the effect considerably better.
I'd want to get minimum 5-6 damage per opponent out of this on average to merit spending 6 mana and a card on it. That's still not great, but it's probably the best inevitability we have access to and that earns some additional points. This feels like it's worth a spot if you expect (A) to get a second activation a majority of the time and (B) that games will typically go several turns beyond 6 mana. The first condition there is killer, so this is probably borderline for the average list. Great inevitability but too slow for most games.
Please come up with an actual single deck that wants reliquary tower over ancient tomb.
Someone mentioned Feather, the Redeemed earlier in the thread. It's up for debate how helpful any colorless land needs to be in a deck as color intensive as a Feather cantrip list, but Tower is almost certainly better than Tomb there.
I'm on the same page as most of the thread. No max hand size is not a great effect and there are usually better cards that you could be running than Tower, but if you do want the effect it's probably tied with or slightly ahead of Thought Vessel as the best way to include it.
I think the only place I've run Tower in recent years is Goreclaw, Terror of Qal Sisma, for the sole reason that the deck was designed as an excessively Timmy list and ran Myojin of Life's Web along with green's big creature draw. Untapping and dropping 5-6 of the better enormous creatures would have been good enough most of the time, but it wasn't nearly as entertaining as dropping 15-20 of them and it was easier to hold a land drop than it was to hold up the 6-9 mana the enablers need at times.
Sliver Queen is a long time favorite card of mine (since I saw it in a Scrye price list, for anyone else who's been playing for a while) that I've never really found a good deck for. Pure slivers has never been super appealing to me, nor has superfriends. I've also tried tokens, lands, and a couple others. The new slivers in MH1 have led to the most recent attempt: 4C control.
I've limited red to just the 5C slivers in the list, and there are some slight adjustments to the manabase to compensate for that. Between fetches, duals, and ramp, I have 20 red sources, which should be enough to play the Queen when I want to. Otherwise, this is primarily a WUBG control list with some slivers that fit the theme a little better. Those are mostly reliant on the Queen's token production to be good and a few are questionable even then (Hibernation Sliver, Opaline Sliver, and Synapse Sliver), but they're the most appealing for a less red zone oriented sliver list. The remainder is pretty typical control goodies - ramp, card draw, answers, etc. Win condition is flooding the board with sliver tokens, flooding the board with super buff sliver tokens, or flooding the board with angel tokens. The Queen can also get into the red zone and finish a player off in three hits in a pinch, though the lack of evasion makes that a little less likely.
So right off the bat, I formatted your list into something more readable that also links to cards and removed the duplicates. That's in the spoiler at the end of the post and you can quote my post to see how I did the formatting. Having that in your opening post is going to get you better responses than what you have now.
Second, let's head off the inevitable notice: Braids, Cabal Minion is banned in this format, silver border cards (i.e. Everythingamajig) aren't legal, and Bioshift has a UG color identity and is therefore not legal in a Meren list. All of those rules can potentially be adjusted after discussion with your group, but you'll want to start with something entirely legal, especially if you don't know the people you'll be playing with.
Now that that's out of the way, you're actually off to a decent start here. I'm seeing three main themes: +1/+1 counters, -1/-1 counters, and sacrifice. Those are all very workable themes in EDH decks, so you're not going to be fighting the format to make things work. That said, the place you really want to start (especially as someone new to the format) is with your support cards, particularly removal, ramp, and card draw. Those are what I'm going to focus on: deckbuilding fundamentals. If you have a decent framework, you can get away with a lot of jank in the rest of the deck. Aside from what I have here, you can also take a look at EDHREC.com. It's particularly good for newer players to the format who don't have the broad card knowledge that you get after years of playing an eternal format. Last point before getting into things, I'll try and keep budget in mind a little for suggestions even though you didn't mention it, but some of this stuff is going to cost more. You should have plenty of options to keep cost down if that's a concern. I'll also warn that this is going to get to be a wall of text in a hurry.
The fact that you've included spot removal and a couple pieces of mass removal means you're off to a good start, and several of your choices are solid EDH cards. Typically, for spot removal you're looking for instant speed and flexibility. In a multiplayer game, you want to give the table every opportunity to answer threats so you don't have to spend a card on it. If someone is swinging at a different player, that's still progressing your game plan and you wouldn't want to stop it. Sorcery speed doesn't give you that option. Similarly, if someone is comboing off on their turn you want to be able to interact when it happens. The best spot removal spell you have now is Assassin's Trophy, which is excellent. Murder is also a solid choice. The other ones you're running are more meta dependent. Walk the Plank is very mana efficient, but sorcery speed is a big knock against it. Abrupt Decay and Fatal Push are mixed. The cost and instant speed are great, but you're much more likely to see higher cost threats in this format than you are in other formats. They're certainly not bad cards, but you probably want to supplement with cards that hit higher CMCs. You're also much more likely to need to answer artifacts and enchantments in this format.
Beast Within is a great card for this - the 3/3 token is negligible, especially because there's no guarantee it will be used against you, and it removes any problem permanent at instant speed. Putrefy is less flexible but still excellent. Hero's Downfall is a strict upgrade to Murder, though I do get the appeal of Murder and walkers are not particularly common in most metas. For just creature removal, Go for the Throat, Victim of Night, and Tragic Slip all have some downsides and many upsides. For noncreatures, Nature's Claim is probably the best. One CMC artifact/enchantment removal with almost no downside is excellent. Return to Nature is a new card that's going to be a regular feature for a while - Naturalize, which is also not bad on its own, plus a GY hate option (coming back to this shortly). There's also Krosan Grip and the upcoming Force of Vigor, which both have a lot of upsides. The other thing you can consider in Meren is effects tied to creatures. Ravenous Chupacabra is solid, unconditional creature removal. Bone Shredder is less open, but the fact that it puts itself in the yard where Meren can reuse it is actually upside here. Caustic Caterpillar and Viridian Zealot do something similar for artifacts and enchantments, while Reclamation Sage is probably the best for a simple ETB.
I mentioned GY hate briefly earlier. That's another thing you want in your list most of the time. You don't need to overload on it, especially if you're running tutors that can find it, but having 1-3 pieces will save you a lot of grief. Bojuka Bog is an easy inclusion in black. It doesn't take anything but some tempo and can proactively clear out yards (reactively if you end up with Crop Rotation). You want some instant speed hate as well. Nihil Spellbomb and Scavenging Ooze are my favorites in these colors, followed by Tormod's Crypt and Withered Wretch. Shred Memory is also good as a piece that can catch people unaware or tutor if you don't need the hate.
The final spot removal area worth highlighting is land destruction. You're not going to make many friends trying to take people off of lands entirely and that's really the only way you're going to be able to play more of a land destroying tempo game, so I wouldn't do that. You do want the ability to answer problematic lands, because there are a lot of them. Some of the spot removal mentioned above can do it, but the other place you want that is in your manabase. Strip Mine and Wasteland are the gold standard but are expensive. I'd personally rank Tectonic Edge after those, but there's an argument for Ghost Quarter, Dust Bowl, and Field of Ruin as well. Opportunity cost to include those is low and upside is high, so you usually want one or two of them.
The next category to think about is mass removal. For the most part, this is referring to creature sweepers. Artifact and enchantment sweepers have a place, but you're more likely to run into board states clogged with creatures than you are any other permanent type in most metas I've played in. Pernicious Deed is a solid one and I'd definitely keep that around. Find // Finality is also good, though you may miss creatures with it from time to time. The gold standards here are Toxic Deluge and Damnation, both of which are pretty pricey. For cheaper stuff, Crux of Fate and Life's Finale are both solid. The new Dead of Winter is also very promising if you can run snow lands. Meren can afford to run a fair number of these, because you have a recursion engine in the command zone. You can also take advantage of your creature sac-ing theme and run some Grave Pact effects. Aside from the eponymous Grave Pact, there's also Dictate of Erebos and Butcher of Malakir. Savra, Queen of the Golgari is a similar one that you already have. If you do want to run some sweepers for noncreature permanents, Bane of Progress is probably the best one, followed by maybe Wave of Vitriol (though it's a decent drop between those). Meren can usually lean on reusing single target effects for this and it's more likely that you're going to need to hit single things anyways.
The next two fundamental areas can kind of be lumped together under the broader heading of velocity. You're going to have better games and more fun when you can reliably do things, and for that to happen you need mana and cards. For mana, that means mana ramp. Meren rewards you for going to creatures, particularly the ones that sac themselves like Sakura-Tribe Elder, Burnished Hart, and Dawntreader Elk. There are also ETB effects like Farhaven Elf and Wood Elves (which can get dual lands with forest typing). Special mention goes to Fertilid, which plays with the +1/+1 counter theme and eventually kills itself for reuse. Beyond those, you're looking at spells and mana rocks. Many metas are less likely to hit your lands and you're in green, so cards like Rampant Growth, Farseek, Nature's Lore, Into the North (if you end up with snow lands), Kodama's Reach, and Cultivate play well. You're looking for relatively inexpensive cards that accelerate your early game mana development. Cards like Boundless Realms are more accurately finishers, where you can overwhelm your opponents with a big resource imbalance late. You also have lots of mana rock options. Some of those, like format staple Sol Ring, are just very efficient. Many of them also come in untapped and give you a decent return on cost. Golgari Signet, the new Talisman of Resilience, Fellwar Stone, Worn Powerstone, Coalition Relic, and Thran Dynamo are all excellent mana rocks.
Card draw you can take in a couple paths. Black will give you straight up draw at the cost of life, while green gives you card draw based on your creatures. Black draw is things like Night's Whisper, Sign in Blood, Ambition's Cost, and Ancient Craving. Harmonize is green but similar. For creature based single shot draw, you're looking at cards that reward swarms like Shamanic Revelation or Regal Force, or at cards that reward big creatures like Rishkar's Expertise or Garruk, Primal Hunter. There are also engines like Skullclamp (arguably the best draw in the game when you're playing/sac-ing small creatures), Necropotence, Guardian Project, Beast Whisperer, Greater Good, Grim Haruspex, and Phyrexian Arena. For those, consider how quickly you want cards and how often they'll be better than the single shot burst draw effects. You usually want a mix of those two categories to keep cards flowing throughout the game.
At this point, I've written a pretty substantial essay on deckbuilding fundamentals and really don't want to write any more. Hopefully this actually gets read, because I'd like to think I have a pretty good handle on the format. If you start with a good mix of these things, it should give you a solid launching point into the format and you can see which of your themed cards you like more than others. At the end of the day, you're really trying to play something you like and something that fits well with your group. As long as you're doing that and having fun with it, you're succeeding in the format.
I dunno, budget to me is a deck I could build with what's in my wallet, from scratch, at my LGS, in one fell swoop.
I don't think I could build anything for $4 so budget magic may not be for me.
The Hanna deck a couple posts up may have actually been budget when it was posted in 2017. Greater Auramancy was probably $20 or so, but most of the other pricey stuff in there was reprinted in masters sets around that time and the list has a lot of low-mid value stuff adding up to the total cost, much of which has climbed in price over the last couple years. Budget lists either change constantly or increase in price over time, sometimes pretty drastically. It could also be aimed at online play, where the total cost is under $20.
As an aside, I remember when I started and it seemed crazy to pay more than $1-2 for a single card at the top end. That mindset has definitely changed.
Had to deal with two of these (original + clone) on the table a couple days ago and they were more of a pain than I was expecting. I had a couple utility lands consistently locked down for a few turns. It's not the best Titan in the format - probably the worst, in fact - but even the bad Titans are still solid cards.
As much so I can organize my thoughts and take a more thorough look at Modern Horizons from an Estrid standpoint as anything, here are all the cards that seem relevant to a more controlling Bant enchantress list.
White
Astral Drift - In the event that I wanted to retool into some Life from the Loam plans, this could work. Having two copies of the effect is a good place to start. That's a very different deck from what I have now, though.
Generous Gift - This probably replaces Beast Within for mostly aesthetic reasons. There's a weak argument that costing W instead of G is better with Serra's Sanctum, but that's realistically minor with how much of each color the deck produces.
On Thin Ice - Would require retooling into a snow manabase. Additional early removal is nice. I don't like that it's creature only, sorcery speed, and weak to land removal in addition to enchantment removal. I don't think I'd take this over any of the numerous O-Ring effects I'm already not running.
Recruit the Worthy - Mostly a consideration because of Estrid's mana generation and the light token themes. This would also play nicely with Wilderness Reclamation, which I've considered before. It's worse than Sprout Swarm in the absence of any tribal synergies so it probably wouldn't be a consideration until I wanted two copies. The big argument against that, discounting the CMC difference (because you can convoke Swarm with the fresh token, as long as you're making more than one), is that Recruit can be paid for using only Serra's Sanctum. If that's active, I usually have more white mana than I know what to do with. If I ever retool into an Earthcraft list, that synergy probably flips the two as well.
Blue
Marit Lage's Slumber - This would obviously require a shift to a snow manabase and I'm still not sure it would be good enough without going even heavier on basic lands. Enchantment based filtering that turns into a large threat late is always worth a look. I don't think it works in this list.
Green
Ayula's Influence - When enchantress gets going, it usually draws more cards than you can use. Turning excess lands into tokens is a decent use for them. The big problem here is that there aren't a lot of other synergies with lands going to the GY and it doesn't do much until you already have an engine going, at which point you should be in good shape.
Land/Artifact
Hall of Heliod's Generosity - Snap include. Rebuilding after enchantment hate currently relies on Estrid's ult, Replenish, Hanna, Ship's Navigator, or drawing out of it. Having another repeatable way to do that that's a littel tougher to disrupt and only occupies a land slot is very desirable. For what's likely the more common case, it also rebuys the protection or hate pieces that tend to draw a lot of removal. Having another powerful utility land also stretches opposing removal - there are only so many Strip Mines at a table, and this, Serra's Sanctum, Gavony Township, and Maze of Ith are almost always worthy targets, even ignoring the more situational ones. I'm very happy to see this.
Prismatic Vista - This deck runs plenty of basics. There's usually an incentive for basics because they're more resilient to land hate and it's always nice to have a basic forest down in case of Utopia Sprawl for pretty much the same reason. This feels like an easy include over a plains or an island.
Waterlogged Grove - While getting choked on cards is usually not a problem outside of a lot of hate or some very bad draws, it does happen. Being able to turn lands into fresh draws is useful in those scenarios or when you already have more mana than you know what to do with, which does happen with Estrid and Sanctum. Having that option on a multicolored land that comes in untapped is great. There's some danger with too many lands that have pain on activation, but I'm usually OK with running several and this only brings the count to two. Outside of games where I see both this and Horizon Canopy early, I wouldn't expect it to be a problem and the potential upside outweighs that heavily in my opinion.
The big wins here are the lands. I'll be adding all three of those, probably in place of Vitu-Ghazi, the City Tree, Island, and Plains. That maintains the same number of white sources and adds a blue source and a green source. It also increases the effective basic forest count, which is useful for Utopia Sprawl. Overall basic count drops slightly, but that's less important unless I add Earthcraft. Not a ton of enchantress support here, but the one card is a big one and the overall manabase improvements are very welcome.
The other one I'd be curious about is Command Beacon. Jaya's activated abilities are pretty mana hungry, so going down a land to recast more cheaply doesn't seem quite as useful here as in other lists until you get up to the third cast or so. Nonbasic lands are also one of the places I've had the most trouble fitting everything that I'd like to run, so those slots are kind of precious to me.
On the whole I like it a lot. It looks like there's a lot of explosive potential with the spell copying and the burn spells, which is a really fun place to be late in the game.
For my list post-MH1, I swapped Magma Phoenix→Tectonic Reformation. I've found that I usually have enough to do that I don't recur the Phoenix all that often. There's a pretty good chance it comes back in for either Jaya Ballard or Dire Fleet Daredevil at some point - I like having the option to recur, even if I don't use it all that often, and I'm feeling a little light on fliers. I might also look into some of the other phoenix and dragons that I've either passed on before or cut from the deck in the past. I've found them really useful for carrying equipment and chipping in some damage to help supplement the burn plan.
I don't have a cut in mind for Prismatic Vista yet. Mountain is an option, because it's not appreciably dropping the basic land count in terms of cards off the top and it's rare for me to actually get all of my basics out of the deck. I haven't wanted to go below 20 in the past, which has me a little hesitant. I also kind of want to fit the Wastes back in the deck once Vista is in, possibly Endbringer as well. That would give me thirteen colorless sources, which is enough to play Endbringer on curve 85% of the time and activate the card draw a turn later 60% of the time. The odds obviously get quite a bit better as the game goes on too. With the chip damage and combat manipulation options on top of that, it seems like it's probably a good fit. The downside being that I'd have to find even more cuts to make that fit.
I'm thinking of trying to do a large scale primer update when MTGNexus opens up. The existing formatting is already a little broken from the Curse acquisition (many years ago) and I never got around to fixing it. The new site is supposed to have very similar BBCode with expanded options, so it's likely some of it will break further and there will be opportunities to pretty it up a bit. It also needs some content reworking, to better reflect some of the new card options and changing thoughts on the old ones. It's tough to promise anything or give a timeline on it because of how much work needs to be done, but it's certainly time to attempt it.
Golos, Tireless Pilgrim is good. I'm kind of burnt out on 5C legendaries that are clearly aimed at EDH right now. This is number 6 in about the last year, including 3 in the last set alone.
All of that said, I love the card and I'm jamming it into more decks than I should. It reminds me a lot of Obsidian Fireheart, which is another card I like a lot and play more than the power dictates. Small, inevitable damage is a lot of fun.
I've only seen Frenzy a couple times, but I've liked it a lot. It's usually drawn a removal spell pretty quickly so I haven't really felt stuck with cards in hand. Accumulating cards in hand while still progressing a board state has been nice. I'm still waiting for the Frenzy play where I hit a long string of lands or something, because it's bound to happen sooner or later. Reformation also plays really nicely with it, because every time you hit a land you basically get to just pay R to move past it, and I'd like to see that interaction happen at least once. Frenzy's slot in the deck is obviously not set in stone, but I've really liked how it plays so far.
Engineer is the one I'm least sure about. The Welder-lite ability is OK but won't grab the things I most want to weld, and I'm not sure how well I can take advantage of the entomb. I like the card a lot, but I haven't gone deep to see if this deck supports it as built.
We also just got the first few M20 spoilers, and they're all Chandra. Chandra, Novice Pyromancer is clearly for a different deck and that's OK. Chandra, Acolyte of Flame is getting closer to good here. I'm not heavy enough on red walkers or cheap instants and sorceries (even if another way to flashback Comet Storm is usually welcome), so that's unlikely to make the cut either. Chandra, Awakened Inferno is in the spoiler below. I love the +2 so much. I don't think it's even that good in a 40 life format, but I love it. I'll happily drop this and spend a bunch of resources trying to protect it so I can stack those emblems. It reminds me a lot of Obsidian Fireheart, which is a card I try and run more often than I probably should. I'll probably try and run both of them simultaneously at some point after Chandra drops.
As an attempt at slightly less biased evaluation, the cons are that 6 CMC is a lot and the damage is glacially slow if you can't stack emblems. The pro is that uncounterable means that you're almost always getting some return on investment, barring a handful of counters that don't actually counter or a stifle effect on the activation. There are very few things more inevitable than an emblem under opponent control as well, which is appealing for a control deck. It also starts at 6, immediately ticks to 8, and the emblem ability is a plus, meaning anyone trying to stop it via creature combat probably has to commit at least a couple creatures. It's reasonable to think that you'll be able to get a second emblem some amount of the time, which makes the effect considerably better.
I'd want to get minimum 5-6 damage per opponent out of this on average to merit spending 6 mana and a card on it. That's still not great, but it's probably the best inevitability we have access to and that earns some additional points. This feels like it's worth a spot if you expect (A) to get a second activation a majority of the time and (B) that games will typically go several turns beyond 6 mana. The first condition there is killer, so this is probably borderline for the average list. Great inevitability but too slow for most games.
I'm definitely still running the card.
I'm on the same page as most of the thread. No max hand size is not a great effect and there are usually better cards that you could be running than Tower, but if you do want the effect it's probably tied with or slightly ahead of Thought Vessel as the best way to include it.
I think the only place I've run Tower in recent years is Goreclaw, Terror of Qal Sisma, for the sole reason that the deck was designed as an excessively Timmy list and ran Myojin of Life's Web along with green's big creature draw. Untapping and dropping 5-6 of the better enormous creatures would have been good enough most of the time, but it wasn't nearly as entertaining as dropping 15-20 of them and it was easier to hold a land drop than it was to hold up the 6-9 mana the enablers need at times.
1 Sliver Queen
\\Sliver Creature
1 Crystalline Sliver
1 Dormant Sliver
1 Gemhide Sliver
1 Hibernation Sliver
1 Manaweft Sliver
1 Mnemonic Sliver
1 Necrotic Sliver
1 Opaline Sliver
1 Psionic Sliver
1 Sliver Hivelord
1 Sliver Legion
1 Synapse Sliver
1 Toxin Sliver
1 Venom Sliver
\\Non-Sliver Creature
1 Baleful Strix
1 Eternal Witness
1 Ophiomancer
1 Scavenging Ooze
1 Snapcaster Mage
\\Enchantment
1 Divine Visitation
1 Kindred Discovery
1 Mirari's Wake
1 Search for Azcanta
1 Sylvan Library
\\Planeswalker
1 Ashiok, Dream Render
1 Narset, Parter of Veils
\\Instant
1 Anguished Unmaking
1 Assassin's Trophy
1 Beast Within
1 Brainstorm
1 Counterspell
1 Despark
1 Dig Through Time
1 Disallow
1 Dissipate
1 Fact or Fiction
1 Frantic Search
1 Heroic Intervention
1 Impulse
1 Mission Briefing
1 Path to Exile
1 Precognitive Perception
1 Sphinx's Revelation
1 Sultai Charm
1 Swords to Plowshares
1 Valorous Stance
1 Austere Command
1 Farseek
1 Kindred Dominance
1 Nature's Lore
1 Painful Truths
1 Ponder
1 Preordain
1 Read the Bones
1 Seasons Past
1 Skyshroud Claim
1 Supreme Verdict
1 Three Visits
1 Tidings
1 Toxic Deluge
1 Treasure Cruise
\\Land
1 Arid Mesa
1 Badlands
1 Bayou
1 Bloodstained Mire
1 Breeding Pool
1 Command Tower
1 Flooded Strand
2 Forest
1 Godless Shrine
1 Hallowed Fountain
2 Island
1 Marsh Flats
1 Misty Rainforest
1 Overgrown Tomb
1 Path of Ancestry
1 Plains
1 Plateau
1 Polluted Delta
1 Reflecting Pool
1 Savannah
1 Scalding Tarn
1 Scrubland
1 Strip Mine
1 Swamp
1 Taiga
1 Temple Garden
1 Tropical Island
1 Tundra
1 Underground Sea
1 Verdant Catacombs
1 Volcanic Island
1 Volrath's Stronghold
1 Wasteland
1 Watery Grave
1 Windswept Heath
1 Wooded Foothills
Second, let's head off the inevitable notice: Braids, Cabal Minion is banned in this format, silver border cards (i.e. Everythingamajig) aren't legal, and Bioshift has a UG color identity and is therefore not legal in a Meren list. All of those rules can potentially be adjusted after discussion with your group, but you'll want to start with something entirely legal, especially if you don't know the people you'll be playing with.
Now that that's out of the way, you're actually off to a decent start here. I'm seeing three main themes: +1/+1 counters, -1/-1 counters, and sacrifice. Those are all very workable themes in EDH decks, so you're not going to be fighting the format to make things work. That said, the place you really want to start (especially as someone new to the format) is with your support cards, particularly removal, ramp, and card draw. Those are what I'm going to focus on: deckbuilding fundamentals. If you have a decent framework, you can get away with a lot of jank in the rest of the deck. Aside from what I have here, you can also take a look at EDHREC.com. It's particularly good for newer players to the format who don't have the broad card knowledge that you get after years of playing an eternal format. Last point before getting into things, I'll try and keep budget in mind a little for suggestions even though you didn't mention it, but some of this stuff is going to cost more. You should have plenty of options to keep cost down if that's a concern. I'll also warn that this is going to get to be a wall of text in a hurry.
The fact that you've included spot removal and a couple pieces of mass removal means you're off to a good start, and several of your choices are solid EDH cards. Typically, for spot removal you're looking for instant speed and flexibility. In a multiplayer game, you want to give the table every opportunity to answer threats so you don't have to spend a card on it. If someone is swinging at a different player, that's still progressing your game plan and you wouldn't want to stop it. Sorcery speed doesn't give you that option. Similarly, if someone is comboing off on their turn you want to be able to interact when it happens. The best spot removal spell you have now is Assassin's Trophy, which is excellent. Murder is also a solid choice. The other ones you're running are more meta dependent. Walk the Plank is very mana efficient, but sorcery speed is a big knock against it. Abrupt Decay and Fatal Push are mixed. The cost and instant speed are great, but you're much more likely to see higher cost threats in this format than you are in other formats. They're certainly not bad cards, but you probably want to supplement with cards that hit higher CMCs. You're also much more likely to need to answer artifacts and enchantments in this format.
Beast Within is a great card for this - the 3/3 token is negligible, especially because there's no guarantee it will be used against you, and it removes any problem permanent at instant speed. Putrefy is less flexible but still excellent. Hero's Downfall is a strict upgrade to Murder, though I do get the appeal of Murder and walkers are not particularly common in most metas. For just creature removal, Go for the Throat, Victim of Night, and Tragic Slip all have some downsides and many upsides. For noncreatures, Nature's Claim is probably the best. One CMC artifact/enchantment removal with almost no downside is excellent. Return to Nature is a new card that's going to be a regular feature for a while - Naturalize, which is also not bad on its own, plus a GY hate option (coming back to this shortly). There's also Krosan Grip and the upcoming Force of Vigor, which both have a lot of upsides. The other thing you can consider in Meren is effects tied to creatures. Ravenous Chupacabra is solid, unconditional creature removal. Bone Shredder is less open, but the fact that it puts itself in the yard where Meren can reuse it is actually upside here. Caustic Caterpillar and Viridian Zealot do something similar for artifacts and enchantments, while Reclamation Sage is probably the best for a simple ETB.
I mentioned GY hate briefly earlier. That's another thing you want in your list most of the time. You don't need to overload on it, especially if you're running tutors that can find it, but having 1-3 pieces will save you a lot of grief. Bojuka Bog is an easy inclusion in black. It doesn't take anything but some tempo and can proactively clear out yards (reactively if you end up with Crop Rotation). You want some instant speed hate as well. Nihil Spellbomb and Scavenging Ooze are my favorites in these colors, followed by Tormod's Crypt and Withered Wretch. Shred Memory is also good as a piece that can catch people unaware or tutor if you don't need the hate.
The final spot removal area worth highlighting is land destruction. You're not going to make many friends trying to take people off of lands entirely and that's really the only way you're going to be able to play more of a land destroying tempo game, so I wouldn't do that. You do want the ability to answer problematic lands, because there are a lot of them. Some of the spot removal mentioned above can do it, but the other place you want that is in your manabase. Strip Mine and Wasteland are the gold standard but are expensive. I'd personally rank Tectonic Edge after those, but there's an argument for Ghost Quarter, Dust Bowl, and Field of Ruin as well. Opportunity cost to include those is low and upside is high, so you usually want one or two of them.
The next category to think about is mass removal. For the most part, this is referring to creature sweepers. Artifact and enchantment sweepers have a place, but you're more likely to run into board states clogged with creatures than you are any other permanent type in most metas I've played in. Pernicious Deed is a solid one and I'd definitely keep that around. Find // Finality is also good, though you may miss creatures with it from time to time. The gold standards here are Toxic Deluge and Damnation, both of which are pretty pricey. For cheaper stuff, Crux of Fate and Life's Finale are both solid. The new Dead of Winter is also very promising if you can run snow lands. Meren can afford to run a fair number of these, because you have a recursion engine in the command zone. You can also take advantage of your creature sac-ing theme and run some Grave Pact effects. Aside from the eponymous Grave Pact, there's also Dictate of Erebos and Butcher of Malakir. Savra, Queen of the Golgari is a similar one that you already have. If you do want to run some sweepers for noncreature permanents, Bane of Progress is probably the best one, followed by maybe Wave of Vitriol (though it's a decent drop between those). Meren can usually lean on reusing single target effects for this and it's more likely that you're going to need to hit single things anyways.
The next two fundamental areas can kind of be lumped together under the broader heading of velocity. You're going to have better games and more fun when you can reliably do things, and for that to happen you need mana and cards. For mana, that means mana ramp. Meren rewards you for going to creatures, particularly the ones that sac themselves like Sakura-Tribe Elder, Burnished Hart, and Dawntreader Elk. There are also ETB effects like Farhaven Elf and Wood Elves (which can get dual lands with forest typing). Special mention goes to Fertilid, which plays with the +1/+1 counter theme and eventually kills itself for reuse. Beyond those, you're looking at spells and mana rocks. Many metas are less likely to hit your lands and you're in green, so cards like Rampant Growth, Farseek, Nature's Lore, Into the North (if you end up with snow lands), Kodama's Reach, and Cultivate play well. You're looking for relatively inexpensive cards that accelerate your early game mana development. Cards like Boundless Realms are more accurately finishers, where you can overwhelm your opponents with a big resource imbalance late. You also have lots of mana rock options. Some of those, like format staple Sol Ring, are just very efficient. Many of them also come in untapped and give you a decent return on cost. Golgari Signet, the new Talisman of Resilience, Fellwar Stone, Worn Powerstone, Coalition Relic, and Thran Dynamo are all excellent mana rocks.
Card draw you can take in a couple paths. Black will give you straight up draw at the cost of life, while green gives you card draw based on your creatures. Black draw is things like Night's Whisper, Sign in Blood, Ambition's Cost, and Ancient Craving. Harmonize is green but similar. For creature based single shot draw, you're looking at cards that reward swarms like Shamanic Revelation or Regal Force, or at cards that reward big creatures like Rishkar's Expertise or Garruk, Primal Hunter. There are also engines like Skullclamp (arguably the best draw in the game when you're playing/sac-ing small creatures), Necropotence, Guardian Project, Beast Whisperer, Greater Good, Grim Haruspex, and Phyrexian Arena. For those, consider how quickly you want cards and how often they'll be better than the single shot burst draw effects. You usually want a mix of those two categories to keep cards flowing throughout the game.
At this point, I've written a pretty substantial essay on deckbuilding fundamentals and really don't want to write any more. Hopefully this actually gets read, because I'd like to think I have a pretty good handle on the format. If you start with a good mix of these things, it should give you a solid launching point into the format and you can see which of your themed cards you like more than others. At the end of the day, you're really trying to play something you like and something that fits well with your group. As long as you're doing that and having fun with it, you're succeeding in the format.
1x Meren of Clan Nel Toth
\\Creature
1x Anowon, the Ruin Sage
1x Ashling, the Extinguisher
1x Avenger of Zendikar
1x Bontu the Glorified
1x Braids, Cabal Minion
1x Corpsejack Menace
1x Crovax the Cursed
1x Crystalline Crawler
1x Drana, Liberator of Malakir
1x Drooling Groodion
1x Flowstone Sculpture
1x God-Eternal Bontu
1x Golgari Guildmage
1x Gonti, Lord of Luxury
1x Hapatra, Vizier of Poisons
1x Josu Vess, Lich Knight
1x Korozda Guildmage
1x Lotleth Troll
1x Marrow Chomper
1x Mazirek, Kraul Death Priest
1x Narnam Renegade
1x Noxious Gearhulk
1x Obelisk Spider
1x Plaguemaw Beast
1x Protean Hydra
1x Rendclaw Trow
1x Reyhan, Last of the Abzan
1x Savra, Queen of the Golgari
1x Shambling Shell
1x Skullbriar, the Walking Grave
1x Spiritmonger
1x Verdurous Gearhulk
1x Vhati il-Dal
1x Walking Ballista
1x Winding Constrictor
1x Yahenni, Undying Partisan
1x Abrupt Decay
1x Arbor Armament
1x Assassin's Trophy
1x Battlegrowth
1x Bioshift
1x Burst of Strength
1x Fatal Push
1x Golgari Charm
1x Murder
1x Stony Strength
\\Enchantment
1x Elephant Grass
1x Forced Adaptation
1x Hardened Scales
1x Pernicious Deed
\\Land
1x Cave of Temptation
1x Forge of Heroes
\\Artifact
1x Animation Module
1x Armory of Iroas
1x Blade of the Bloodchief
1x Dragon Blood
1x Everythingamajig
1x Sword of Truth and Justice
1x Bone Splinters
1x Enter the Unknown
1x Find // Finality
1x Vraska's Stoneglare
1x Walk the Plank
\\Planeswalker
1x Garruk, the Veil-Cursed
1x Liliana, Death Wielder
1x Vraska, Golgari Queen
1x Vraska, Regal Gorgon
The Hanna deck a couple posts up may have actually been budget when it was posted in 2017. Greater Auramancy was probably $20 or so, but most of the other pricey stuff in there was reprinted in masters sets around that time and the list has a lot of low-mid value stuff adding up to the total cost, much of which has climbed in price over the last couple years. Budget lists either change constantly or increase in price over time, sometimes pretty drastically. It could also be aimed at online play, where the total cost is under $20.
As an aside, I remember when I started and it seemed crazy to pay more than $1-2 for a single card at the top end. That mindset has definitely changed.
There are a bunch of other things that I'm interested in, though they don't necessarily have immediate decks to drop into. The biggest ones are the other horizon lands, the enemy talismans, Yawgmoth, Thran Physician, and Ice-Fang Coatl. Giver of Runes, Fallen Shinobi, Dead of Winter, Wrenn and Six, and the Swords are also all high on my list of pickups. I also really like the entire Morphling cycle, so I'll definitely pick up an Endling even if it never has a home other than Mairsil, the Pretender.
White
- Astral Drift - In the event that I wanted to retool into some Life from the Loam plans, this could work. Having two copies of the effect is a good place to start. That's a very different deck from what I have now, though.
- Generous Gift - This probably replaces Beast Within for mostly aesthetic reasons. There's a weak argument that costing W instead of G is better with Serra's Sanctum, but that's realistically minor with how much of each color the deck produces.
- On Thin Ice - Would require retooling into a snow manabase. Additional early removal is nice. I don't like that it's creature only, sorcery speed, and weak to land removal in addition to enchantment removal. I don't think I'd take this over any of the numerous O-Ring effects I'm already not running.
- Recruit the Worthy - Mostly a consideration because of Estrid's mana generation and the light token themes. This would also play nicely with Wilderness Reclamation, which I've considered before. It's worse than Sprout Swarm in the absence of any tribal synergies so it probably wouldn't be a consideration until I wanted two copies. The big argument against that, discounting the CMC difference (because you can convoke Swarm with the fresh token, as long as you're making more than one), is that Recruit can be paid for using only Serra's Sanctum. If that's active, I usually have more white mana than I know what to do with. If I ever retool into an Earthcraft list, that synergy probably flips the two as well.
Blue
- Marit Lage's Slumber - This would obviously require a shift to a snow manabase and I'm still not sure it would be good enough without going even heavier on basic lands. Enchantment based filtering that turns into a large threat late is always worth a look. I don't think it works in this list.
Green
- Ayula's Influence - When enchantress gets going, it usually draws more cards than you can use. Turning excess lands into tokens is a decent use for them. The big problem here is that there aren't a lot of other synergies with lands going to the GY and it doesn't do much until you already have an engine going, at which point you should be in good shape.
Land/Artifact
- Hall of Heliod's Generosity - Snap include. Rebuilding after enchantment hate currently relies on Estrid's ult, Replenish, Hanna, Ship's Navigator, or drawing out of it. Having another repeatable way to do that that's a littel tougher to disrupt and only occupies a land slot is very desirable. For what's likely the more common case, it also rebuys the protection or hate pieces that tend to draw a lot of removal. Having another powerful utility land also stretches opposing removal - there are only so many Strip Mines at a table, and this, Serra's Sanctum, Gavony Township, and Maze of Ith are almost always worthy targets, even ignoring the more situational ones. I'm very happy to see this.
- Prismatic Vista - This deck runs plenty of basics. There's usually an incentive for basics because they're more resilient to land hate and it's always nice to have a basic forest down in case of Utopia Sprawl for pretty much the same reason. This feels like an easy include over a plains or an island.
- Waterlogged Grove - While getting choked on cards is usually not a problem outside of a lot of hate or some very bad draws, it does happen. Being able to turn lands into fresh draws is useful in those scenarios or when you already have more mana than you know what to do with, which does happen with Estrid and Sanctum. Having that option on a multicolored land that comes in untapped is great. There's some danger with too many lands that have pain on activation, but I'm usually OK with running several and this only brings the count to two. Outside of games where I see both this and Horizon Canopy early, I wouldn't expect it to be a problem and the potential upside outweighs that heavily in my opinion.
The big wins here are the lands. I'll be adding all three of those, probably in place of Vitu-Ghazi, the City Tree, Island, and Plains. That maintains the same number of white sources and adds a blue source and a green source. It also increases the effective basic forest count, which is useful for Utopia Sprawl. Overall basic count drops slightly, but that's less important unless I add Earthcraft. Not a ton of enchantress support here, but the one card is a big one and the overall manabase improvements are very welcome.