I mentioned this in the other thread, but flashback spells, that target a creature you control, will get returned by Feather, as flashback just looks that Feather's replacement effects sends the card to exile and doesn't care if it later comes back. Although there weren't a ton of good RW spells with flashback, there is one card that I think you could really do with: Past In Flames. For all the instants and sorceries you managed to lose, here's the chance to bring them back to your hand!
They were also talking about an Arcane / Splice package, but that probably takes more away from the deck.
Hey, according to the other thread, Feather will put cards with flashback back into your hand, since flashback is also a replacement effect that requires the card go to exile instead of any other place and Feather's ability does indeed send it to exile. So here's the cards that 1) have flashback 2) target something and 3) can be used in an RW EDH deck:
-Bash to Bits: Probably unhelpful to destroy our own stuff unless we go in hard on temporary theft of opponent's cards. That being said, a heavy artifact build could see it as "trade my worst artifact for their best artifact" and be happy.
-Blast from the Past: Most people won't let you play it, but it seems like it could actually be not terrible in this deck if your playgroup allows it.
-Burning Oil: Similar to Bash to Bits, deals a bit too much damage to your own stuff to be worth the cost. In a deck with expendable 1/1 tokens, it's a 6-mana repeatable Gideon's Reproach.
-Conflagrate: Ooh baby, this is an endlessly repeatable X-spell -- and not only is it a decent one that can be looped on its own even without flashback, it also can be flashbacked to our hand to repeat next turn! Any strategy that makes lots of either cards or mana (or, with the new Neheb, both) can convert both into damage where it likes. It might still be a bit expensive, though.
-Devil's Play: Similar to above, it's XRRRR to deal X damage to something. Expensive but not the worst for a huge ramp deck.
-Earth Rift: I think we can do better than this, but I guess trading a Plains for a utility land could be alrightish. 11 mana's a rough cycle cost, though.
-Embolden: This might not end up any good, but I think it's worth testing. 5 mana to prevent 7 damage a turn cycle (plus 1 to Feather) isn't so impressive, but it's an awesome enabler for heroic at a pretty good rate.
-Engulfing Flames: 5 mana is too expensive for 1 damage, no matter how repeatable.
-Firebolt: Better than Engulfing Flames, but still not good -- 6 mana for 2 damage is still too much.
-Flaming Gambit: I have no idea if this is good or not, I have no idea how to evaluate it, but it seems pretty bad.
-Gaze of Justice: 7 mana, tap 6 creatures, and exile one of your own spare 1/1s, all for a repeatable exile effect? Exile's nice and all, but Spine of Ish Sah is probably better.
-Geistflame: Why do they keep making this effect? 5 mana is still too much.
-Lava Dart: ...probably still bad? It's cheaper, but still just as ineffective.
-Lightning Surge: Maybe alright removal if you have expendable tokens, but still probably way too expensive.
-Nightbird's Clutches: This could achieve mediocrity in a fairly aggro deck.
- ** Past In Flames ** No, it doesn't recur itself. It just recurs everything else. Hot diggity, here's some card advantage.
-Reckless Charge: 4 mana to repeatedly give something +6/+0? That's pretty big, but I bet an equipment would do the job better. Worth considering at least in a heavily heroic-focused aggro deck -- or, maybe, a Voltron commander-damage strategy.
-Recoup: A worse Past in Flames (and similarly not repeatable on its own), but this is still a pretty good card, if you manage to lose one of your sorceries and want it back.
-Scorching Missile: Literally 14 mana to cycle. Pass.
-Seize the Day: 7 mana's not so much, and 3 combat phases a turn for multiple turns in a row will kill someone darn quickly.
-Spirit Flare: Huh. This does something, and it works well with Feather... but what it does is still not all that impressive. Better than Burning Oil, I guess?
-Volley of Boulders: You know what? This may be 15 mana to cycle, but 11 damage to their face each cycle isn't too bad. I dunno. Probably unplayable, but it is pretty funny.
Naive question alert: Why, outside of Zendikar blocks, don't they just call it "landfall?" Is it because it would push the card into evergreen territory and WotC R&D doesn't want it to be an evergreen keyword?
It's a good question. The name is self-descriptive, and they would still spell out the trigger, so it's not like it would make things hard for noobs. And they use it often enough to warrant being deciduous (if not evergreen).
I think it's a signalling problem. This is already a super complex set (as planeswalkers at uncommon will do...), which I imagine helped contribute to the whole 'two named mechanics' thing. For a new player being introduced to Magic, there's already so many things to learn -- another mechanic, even a self-descriptive one, might be too much.
They always talk about how they got complaints about Mercadian Masques not having mechanics, despite having a bunch of them (Rebels, Mercenaries, and Spellshapers as the most visible) -- because they didn't explicitly have ability words attached to them, so they were just seen as individual cards. Players' understanding of the set, at least at the time, didn't become centered around the abilities (despite the 4 full cycles of Spellshapers, or 30ish Rebels/Mercenaries). Compare to today: someone bringing up, say, Amonkhet, would probably mention Embalm / Eternalize, exert, cycling, or even -1/-1 counters, before they would mention the Cartouche/Trial double cycle or the Desert mechanics, even though there's a relatively comparable number of Deserts to exert cards (across both sets, 19 to 28, with 10 to 0 cards without the mechanic that call it out by name eg "if you control a desert...").
With that in mind, I'm assuming this is a deliberate attempt to go in the other direction -- to not provide that cohesive unity. If a new player sees a cool ability involving proliferate and land drops, they may or may not get the card, but either way they can move on until it comes up in game. If they see something labeled 'landfall', though, that's an indication that they should remember and learn that term, and look out for it in other places in the set -- when, in fact, landfall isn't even a deliberate theme of Ravnica and just happens to come up on one or two cards.
I'd agree that Reservoir seems too expensive; Trash for Treasure takes enough moving pieces that I don't think you'd want to have to do it twice, and Reservoir on its own just isn't good enough against decks that aren't Burn. That is, once you have Citadel on the field, you'll probably win without the help of Reservoir, and if you don't have Citadel, Reservoir isn't going to be good enough.
Regardless, it's worth testing, since this is all theorycrafting at this point. What I want to find is a second alternative to Trash for Treasure; just one way to sneak it in isn't consistent enough, and I think hardcasting is probably out given the triple-black cost.
Alternatively, you could also just play Future Sight and commit to playing primarily zero-cost artifacts, as a much worse backup option. That's just as color-intensive to cast, though, and can't be Trash/Treasured.
Honestly, I can see this in mono-R. Flavorwise, I don't think the self-sacrifice necessarily implies B; it could be flavored, for instance, as a potion of blind love/rage/whatever, that inspires the target to do their best to reach the Shaman, no matter what. (Or whatever other flavor you want; the whole point of flavor is you can kind of make pretty much anything work.) To me, the self-sacrifice argument is also really undermined by the fact that you might also use it to make them waste pump spells, etc.
Now, my mechanical arguments:
1) I agree that Worst Fears is too far from the effect, and Word of Command too far in the past, to indicate much of relevance.
2) The focus on instants and sorceries, preferably with a target, makes it odd to call this black to me. Yes, black gets Duress, but does it target instants/sorceries specifically? Doing a Gatherer search, I did find Collective Brutality, but that's it (please correct me if you find something else) -- and that specific card is less clear too given its modality, being designed to handle creatures in one mode, I/S in another.
3) In contrast, I don't think it needs to be said that RU are well-known for dealing with instants/sorceries.
4) So, in Ravnica I'd say Izzet and be done. Everywhere else, though, why add extra colors? Between R and U, both can do spell-stealing effects, so you don't need both.
5) In that case, which color fits best to the effect? To me, the randomness in the card's design pushes it to red -- blue is much more methodical (Talent of the Telepath, which is more likely to hit something by giving you lots to choose) or is reactive (counterspells, etc.). This is a proactive option for preemptively removing a card from an opponent's hand and stealing it for yourself. In a case where it could go to either color, I would seize on that distinction (R from opp's hand, U from opp's library) and use it to justify it as mono-R, since little differences like that are how we keep R and U distinct while maintaining fresh mechanical design space (see Control Magic vs Act of Treason dichotomy).
6) Flagbearer effect is interesting and relevant, but I think this card as a whole makes no sense as a white card -- stealing resources, interacting with an opponent's hand outside of Balance effects, neither are remotely white at all. UW and RW could be flavored away pretty well, though, I'll concede that.
So: I'd vote mono-R as best, with RU as second-best and UW/RW/U as additional reasonable options. Honestly, though, B makes no sense to me -- it doesn't frequently interact with instants and sorceries, it doesn't do thievery all that often unless it's paired with U / stealing from graveyard / etc., and even when this functions as discard, it so frequently will do so much more (or do it with such different consequences) that I don't think it's an apt comparison at all.
-Tezz looks cool; kinda generic good artifact stuff, but the +2's really good in a dedicated deck.
-Vraska: I don't care if she's less powerful. Something nobody's mentioned so far: the art here is so cool. God, that's awesome. Fun uncommon, too.
-V's Finisher: Seen it already. Kinda narrow, a fine common. meh
-Ajani: Yeah, weird art and effect, but very generically powerful without feeling generic himself, so I'll take it. -2's great, effect is good, that's enough.
-Ignite the Beacon: Wait, so is Ajani dying? Nooo! Ajani was supposed to return to Theros, we've been waiting on that story for so long!
-Interplanar Beacon: Meh, superfriends enabler, that's all.
-Emergence Zone: Wait this is really good tho. Nice!
-No Escape: Decent common honestly
-Flux Channeler: Yes this is broken, why do you ask? I actually wonder if we'll see this in a new Modern Infect deck -- they play so many cheap pump spells already, this provides an alt-win that doesn't rely on combat. They're probably way too fast for that, though. In any case, this is weird 'cause I thought speculation mainly pointed to Mirrodin fairly soon after RtRtRavnica, and I'd be very surprised if they do Mirrodin without infect and proliferate -- and that would to me make it weird to put proliferate in another nearby set.
-Herald of the Dreadhorde: Since this is the first amass card on this list: I love amass! I think this mechanic is super cool. Also, this card on its own seems fun in limited and maybe even alright in some sort of Aristocrats style deck.
-Invade the City: Standard Izzet fare, but actually I can see it being pretty powerful -- it'd be easy in a Drakes deck to make this a 3/3 T3 or 4/4-5/5 T4, and it gets better as the game goes on.
-Dreadhorde Invasion: It's nothing close to a Bitterblossom. In a more dedicated amass deck -- or, even better, an Aristocrats deck that can use the tokens -- it can be a decent card, and it seems fun to play with.
-Widespread Brutality: This is a great example of the cool things amass can do. Quite powerful -- I don't know how, but I bet it'll get played in Standard somehow.
-Liliana: Yes this is sick. Yes I want this for my Sidisi edh deck. Otherwise, though, just a good top-end threat that deals with anything your opponent has left to attack it and then makes blockers/attackers.
-Ravnica at War: I wish there weren't so many exile cards in general, much less wraths, but this is narrow enough that I hope not to see much of it. Good effect and well-costed, just a personal taste for how exile ought to be used.
I'll also just mention the other cards we've seen so far:
-Ob Nixilis: This is a great uncommon. Kinda weird on an empty board, but big card advantage for your expendable cards, removal (however painful) for their threats, and some minor ping damage.
-Ob Nixilis's Cruelty: Jeez, that's a common?
-Tibalt: This is so cool. Very excited. This is pretty much a perfect Tibalt card. My sole complaint was I was hoping Tibalt would be the first one-mana planeswalker, but this is pretty cool too. Also, is it just me, or are getting rid of these planeswalkers through combat going to be very annoying if they don't use their minus abilities?
-Tibalt's thingbobber: Weird having a normal uncommon alongside all the planeswalkers. Meh.
-Time Wipe: This is awesome, and a good wrath effect. We may never again have Wrath of God in Standard, but I'm actually pretty happy with the 5-mana wipes and 4-mana conditional wipes that we've been getting -- I think it's been leading to more interesting designs.
To be clear, this is a different rules interaction than if, say, Oblivion Ring had been cast with flash somehow (through Leyline of Anticipation or whatnot). In that case, there are two separate triggers -- one definitely exiling regardless if the Ring is still on the field, the other returning once the Ring dies -- and so your opponent's creature would actually be exiled permanently if played in the way you describe above casting Naturalize in response to the enter-the-battlefield trigger, because the leave-the-battlefield returning trigger would resolve first (having nothing to return) and then the exiling trigger. If played as Ring enters, exiles something, then is destroyed and the creature returns to the battlefield, then the creature in question returns as a new object and thus would no longer be attacking.
All that is because of the old wording for Oblivion Ring type effects -- one trigger to enter, one trigger on return. Modern Ring-style cards use the newer "exiles until" phrasing, which has the above sorts of loopholes closed by defining in the rules the response to these sorts of edge cases -- in this case, if the Ring left the battlefield before the trigger resolves, the rules definitions for 'until' say that nothing happens at all (see the above post for the exact Comprehensive Rules citation).
Not at all blue. Maro's written lots about the color pie -- I found particularly this article: Mechanical Color Pie. I think you're going for a Polymorph type flavor, which is something thatblue does occasionally -- but it's a fine line, and I really do think this particular card would be unlikely to be printed. It's true that it's probably pretty balanced, and an interesting card, but I really question it in mono-blue -- considering the complaints about Reality Shift when it was printed.
I dunno. I do think it'd be pretty cool to play with, but I think it's dangerous giving that sort of unconditional removal to blue, even with the card advantage.
Just a note -- combining Earthquake and Platinum Angel won't go as well for you as you'd like, since both you and the Angel will still have damage marked on them. You'll go to (for instance) -5 life but won't die -- but then the Angel will die from lethal damage, and then you'll die.
EDIT: Hey Earthquake doesn't hit flying creatures. Okay, other X-burn spells that hit creatures and players.
Agreed the exchange almost certainly has to go -- besides the previous commenter's concern about the morph-like stackless state of the exchange at the moment, it also seems like it would make the board state excessively difficult to evaluate on both sides. I would at least add a mana cost to the switching ability, if you choose to keep it (I don't really understand the flavor of it).
I also suggest making it sorcery-speed, for things like the following situation: you control one each of Bear Fold and Bird Fold attached to papers. I have a hand with 50 copies of Shredding Winds and infinite mana. However, I will never be able to destroy the Bird Fold; every time I cast a Wind, you switch in response and the spell fizzles; if you cast another one in response, I switch again in response, fizzle it, then switch back; and so on.
I dunno. Maybe these changes take away from your goal for the mechanic; that said, the mechanical child of banding and the Flagbearer mechanic at common is 1) anachronistic and probably no longer accepted under NWO due to board state and mechanical complexity, and 2) probably really weird to play with in some relatively common edge cases -- it's new, but it's weird and probably confusing/not straightforward.
Also, the whole 'discard and put into play' mechanic is weird too, but I concede I don't have a better suggestion and that it, at least, makes sense and doesn't have too many edge cases I can think of, besides eg letting Tormod's Crypt counter your spell but not actual Counterspell.
Anyway: that's a lot of mechanical nitpicks. Flavorfully, I think it's a very cool and wacky mechanic, and I certainly think there's room for designing some cool cards with it, so props on all those points.
Consider Llanowar Reborn for an example of a +1/+1 counter on a land that doesn't do anything. +1/+1 counters can exist on lands, they just won't do anything since there's no power/toughness to be boosted.
121.3. If a permanent has both a +1/+1 counter and a -1/-1 counter on it, N +1/+1 and N -1/-1 counters are removed from it as a state-based action, where N is the smaller of the number of +1/+1 and -1/-1 counters on it. See rule 704.
Note that the counter-negation rule still applies to all permanents, though, not just creatures.
As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.
All creatures. Even if Nexus has a +1/+1 counter on it, that does not mean it has toughness or that it's a creature. Toxic Deluge will not do anything to something that's not a creature. So, assuming Nexus is a land and not a creature at the time (aka you didn't activate its ability that turn prior to your opponent casting Deluge) -- nothing happens, because Deluge applies to creatures and Nexus isn't one.
704.5f If a creature has toughness 0 or less, it's put into its owner's graveyard. Regeneration can't replace this event.
On the other hand, if Nexus is a creature (say, for instance, you activated it on your opponent's upkeep, and they cast Deluge in their main phase): then the above state-based action applies. Immediately following Deluge resolving, the game looks around, realizes that Nexus is a creature that now has <0 toughness, and destroys it, just how you'd expect it to do to any other 1/1 with a -1/-1 counter on it.
Now, here's a hypothetical scenario: you activate Inkmoth's ability, making it a 1/1 until end of turn. You control a couple of Glorious Anthems, meaning that Nexus is actually a 3/3 or something. Your opponent casts Black Sun's Zenith for 1, putting a -1/-1 counter on Nexus -- making it a 2/2. The turn ends, and Nexus reverts to being a land. Your opponent casts Cleanfall, destroying your Anthems. What happens?
121.1a A +X/+Y counter on a creature or on a creature card in a zone other than the battlefield, where X and Y are numbers, adds X to that object's power and Y to that object's toughness. Similarly, -X/-Y counters subtract from power and toughness. See rule 613.3.
Well, Nexus is a land with a -1/-1 counter on it. The counter doesn't just go away when Nexus stops being a creature; it just doesn't do anything, because Nexus isn't a creature and so the counter has no built-in effect on it (that is, the above rule only applies to creatures). And that's why, incidentally, a bunch of the rules in the comp rules regarding +1/+1 counters refer to 'permanent's with +1/+1 counters on them -- because you can't be sure it's a creature.
Note, though, that if you then chose to activate the ability and make Nexus a creature, the counter would suddenly have something to do again, Nexus would be a 0/0 creature, and it would die just as before. Note that the above extended example gets weirder if you use, eg, Giant Growth instead of Anthems, because I don't remember how end-of-turn effects work here (whether Nexus becomes a land or loses its toughness boost first) -- but luckily you didn't ask that and probably won't run into any time soon.
Yeah... check out Belligerent Hatchling. That's an albino Medusa-wolf that spits bees. Why? Who knows.
Lorwyn art is usually awesome, but is often thematically incomprehensible. Primalcrux might be a case of the opposite problem: you know the thematic material (wood elemental!), you just can't understand any other aspect of the art.
If I hazard a guess, I would say it's some sort of antlered beast -- probably a moose deer et al -- the two 3-pronged clusters are legs (unusually widely placed), and there's also some random wood sticking out above the left(rel to beast, our right) leg.
Huh... Tibalt, the Fiend-Blooded is all of a sudden right at the very top-end of acceptable power level, possibly even OP. Choice of Damnations is probably too powerful to be acceptable. Goldenglow Moth is an awesome early-game play. Hat Stand is a game-warpingly powerful card, and forms something akin to the Exarch/Pestermite half of the Twin combo with Force of Savagery. Dimir Charm and the like kill half the format. Char-Rumbler is a super powerful play.
Presumably he's using the second ability on both of the cards. it doesn't go infinite since Magosi enters tapped, but he does get 2 turns for everyone else's turns, assuming he can keep sacrificing artifacts. It's not broken -- arguably better than, say, Opposition or Time Warp -- but still really annoying.
They were also talking about an Arcane / Splice package, but that probably takes more away from the deck.
-Bash to Bits: Probably unhelpful to destroy our own stuff unless we go in hard on temporary theft of opponent's cards. That being said, a heavy artifact build could see it as "trade my worst artifact for their best artifact" and be happy.
-Blast from the Past: Most people won't let you play it, but it seems like it could actually be not terrible in this deck if your playgroup allows it.
-Burning Oil: Similar to Bash to Bits, deals a bit too much damage to your own stuff to be worth the cost. In a deck with expendable 1/1 tokens, it's a 6-mana repeatable Gideon's Reproach.
- Conflagrate : Ooh baby, this is an endlessly repeatable X-spell -- and not only is it a decent one that can be looped on its own even without flashback, it also can be flashbacked to our hand to repeat next turn! Any strategy that makes lots of either cards or mana (or, with the new Neheb, both) can convert both into damage where it likes. It might still be a bit expensive, though.
- Devil's Play : Similar to above, it's XRRRR to deal X damage to something. Expensive but not the worst for a huge ramp deck.
-Earth Rift: I think we can do better than this, but I guess trading a Plains for a utility land could be alrightish. 11 mana's a rough cycle cost, though.
- Embolden : This might not end up any good, but I think it's worth testing. 5 mana to prevent 7 damage a turn cycle (plus 1 to Feather) isn't so impressive, but it's an awesome enabler for heroic at a pretty good rate.
-Engulfing Flames: 5 mana is too expensive for 1 damage, no matter how repeatable.
-Firebolt: Better than Engulfing Flames, but still not good -- 6 mana for 2 damage is still too much.
-Flaming Gambit: I have no idea if this is good or not, I have no idea how to evaluate it, but it seems pretty bad.
-Gaze of Justice: 7 mana, tap 6 creatures, and exile one of your own spare 1/1s, all for a repeatable exile effect? Exile's nice and all, but Spine of Ish Sah is probably better.
-Geistflame: Why do they keep making this effect? 5 mana is still too much.
-Lava Dart: ...probably still bad? It's cheaper, but still just as ineffective.
-Lightning Surge: Maybe alright removal if you have expendable tokens, but still probably way too expensive.
-Nightbird's Clutches: This could achieve mediocrity in a fairly aggro deck.
- ** Past In Flames ** No, it doesn't recur itself. It just recurs everything else. Hot diggity, here's some card advantage.
-Reckless Charge: 4 mana to repeatedly give something +6/+0? That's pretty big, but I bet an equipment would do the job better. Worth considering at least in a heavily heroic-focused aggro deck -- or, maybe, a Voltron commander-damage strategy.
-Recoup: A worse Past in Flames (and similarly not repeatable on its own), but this is still a pretty good card, if you manage to lose one of your sorceries and want it back.
-Scorching Missile: Literally 14 mana to cycle. Pass.
- Seize the Day : 7 mana's not so much, and 3 combat phases a turn for multiple turns in a row will kill someone darn quickly.
-Spirit Flare: Huh. This does something, and it works well with Feather... but what it does is still not all that impressive. Better than Burning Oil, I guess?
-Volley of Boulders: You know what? This may be 15 mana to cycle, but 11 damage to their face each cycle isn't too bad. I dunno. Probably unplayable, but it is pretty funny.
Just as a note, I can't tell you when or how, but someone's made and is successfully selling plushies.
I think it's a signalling problem. This is already a super complex set (as planeswalkers at uncommon will do...), which I imagine helped contribute to the whole 'two named mechanics' thing. For a new player being introduced to Magic, there's already so many things to learn -- another mechanic, even a self-descriptive one, might be too much.
They always talk about how they got complaints about Mercadian Masques not having mechanics, despite having a bunch of them (Rebels, Mercenaries, and Spellshapers as the most visible) -- because they didn't explicitly have ability words attached to them, so they were just seen as individual cards. Players' understanding of the set, at least at the time, didn't become centered around the abilities (despite the 4 full cycles of Spellshapers, or 30ish Rebels/Mercenaries). Compare to today: someone bringing up, say, Amonkhet, would probably mention Embalm / Eternalize, exert, cycling, or even -1/-1 counters, before they would mention the Cartouche/Trial double cycle or the Desert mechanics, even though there's a relatively comparable number of Deserts to exert cards (across both sets, 19 to 28, with 10 to 0 cards without the mechanic that call it out by name eg "if you control a desert...").
With that in mind, I'm assuming this is a deliberate attempt to go in the other direction -- to not provide that cohesive unity. If a new player sees a cool ability involving proliferate and land drops, they may or may not get the card, but either way they can move on until it comes up in game. If they see something labeled 'landfall', though, that's an indication that they should remember and learn that term, and look out for it in other places in the set -- when, in fact, landfall isn't even a deliberate theme of Ravnica and just happens to come up on one or two cards.
Regardless, it's worth testing, since this is all theorycrafting at this point. What I want to find is a second alternative to Trash for Treasure; just one way to sneak it in isn't consistent enough, and I think hardcasting is probably out given the triple-black cost.
Alternatively, you could also just play Future Sight and commit to playing primarily zero-cost artifacts, as a much worse backup option. That's just as color-intensive to cast, though, and can't be Trash/Treasured.
Anyway, I just really pray this isn't Elspeth.
Now, my mechanical arguments:
1) I agree that Worst Fears is too far from the effect, and Word of Command too far in the past, to indicate much of relevance.
2) The focus on instants and sorceries, preferably with a target, makes it odd to call this black to me. Yes, black gets Duress, but does it target instants/sorceries specifically? Doing a Gatherer search, I did find Collective Brutality, but that's it (please correct me if you find something else) -- and that specific card is less clear too given its modality, being designed to handle creatures in one mode, I/S in another.
3) In contrast, I don't think it needs to be said that RU are well-known for dealing with instants/sorceries.
4) So, in Ravnica I'd say Izzet and be done. Everywhere else, though, why add extra colors? Between R and U, both can do spell-stealing effects, so you don't need both.
5) In that case, which color fits best to the effect? To me, the randomness in the card's design pushes it to red -- blue is much more methodical (Talent of the Telepath, which is more likely to hit something by giving you lots to choose) or is reactive (counterspells, etc.). This is a proactive option for preemptively removing a card from an opponent's hand and stealing it for yourself. In a case where it could go to either color, I would seize on that distinction (R from opp's hand, U from opp's library) and use it to justify it as mono-R, since little differences like that are how we keep R and U distinct while maintaining fresh mechanical design space (see Control Magic vs Act of Treason dichotomy).
6) Flagbearer effect is interesting and relevant, but I think this card as a whole makes no sense as a white card -- stealing resources, interacting with an opponent's hand outside of Balance effects, neither are remotely white at all. UW and RW could be flavored away pretty well, though, I'll concede that.
So: I'd vote mono-R as best, with RU as second-best and UW/RW/U as additional reasonable options. Honestly, though, B makes no sense to me -- it doesn't frequently interact with instants and sorceries, it doesn't do thievery all that often unless it's paired with U / stealing from graveyard / etc., and even when this functions as discard, it so frequently will do so much more (or do it with such different consequences) that I don't think it's an apt comparison at all.
-Tezz looks cool; kinda generic good artifact stuff, but the +2's really good in a dedicated deck.
-Vraska: I don't care if she's less powerful. Something nobody's mentioned so far: the art here is so cool. God, that's awesome. Fun uncommon, too.
-V's Finisher: Seen it already. Kinda narrow, a fine common. meh
-Ajani: Yeah, weird art and effect, but very generically powerful without feeling generic himself, so I'll take it. -2's great, effect is good, that's enough.
-Ignite the Beacon: Wait, so is Ajani dying? Nooo! Ajani was supposed to return to Theros, we've been waiting on that story for so long!
-Interplanar Beacon: Meh, superfriends enabler, that's all.
-Emergence Zone: Wait this is really good tho. Nice!
-No Escape: Decent common honestly
-Flux Channeler: Yes this is broken, why do you ask? I actually wonder if we'll see this in a new Modern Infect deck -- they play so many cheap pump spells already, this provides an alt-win that doesn't rely on combat. They're probably way too fast for that, though. In any case, this is weird 'cause I thought speculation mainly pointed to Mirrodin fairly soon after RtRtRavnica, and I'd be very surprised if they do Mirrodin without infect and proliferate -- and that would to me make it weird to put proliferate in another nearby set.
-Herald of the Dreadhorde: Since this is the first amass card on this list: I love amass! I think this mechanic is super cool. Also, this card on its own seems fun in limited and maybe even alright in some sort of Aristocrats style deck.
-Invade the City: Standard Izzet fare, but actually I can see it being pretty powerful -- it'd be easy in a Drakes deck to make this a 3/3 T3 or 4/4-5/5 T4, and it gets better as the game goes on.
-Dreadhorde Invasion: It's nothing close to a Bitterblossom. In a more dedicated amass deck -- or, even better, an Aristocrats deck that can use the tokens -- it can be a decent card, and it seems fun to play with.
-Widespread Brutality: This is a great example of the cool things amass can do. Quite powerful -- I don't know how, but I bet it'll get played in Standard somehow.
-Liliana: Yes this is sick. Yes I want this for my Sidisi edh deck. Otherwise, though, just a good top-end threat that deals with anything your opponent has left to attack it and then makes blockers/attackers.
-Ravnica at War: I wish there weren't so many exile cards in general, much less wraths, but this is narrow enough that I hope not to see much of it. Good effect and well-costed, just a personal taste for how exile ought to be used.
I'll also just mention the other cards we've seen so far:
-Ob Nixilis: This is a great uncommon. Kinda weird on an empty board, but big card advantage for your expendable cards, removal (however painful) for their threats, and some minor ping damage.
-Ob Nixilis's Cruelty: Jeez, that's a common?
-Tibalt: This is so cool. Very excited. This is pretty much a perfect Tibalt card. My sole complaint was I was hoping Tibalt would be the first one-mana planeswalker, but this is pretty cool too. Also, is it just me, or are getting rid of these planeswalkers through combat going to be very annoying if they don't use their minus abilities?
-Tibalt's thingbobber: Weird having a normal uncommon alongside all the planeswalkers. Meh.
-Time Wipe: This is awesome, and a good wrath effect. We may never again have Wrath of God in Standard, but I'm actually pretty happy with the 5-mana wipes and 4-mana conditional wipes that we've been getting -- I think it's been leading to more interesting designs.
Very excited for this set!
All that is because of the old wording for Oblivion Ring type effects -- one trigger to enter, one trigger on return. Modern Ring-style cards use the newer "exiles until" phrasing, which has the above sorts of loopholes closed by defining in the rules the response to these sorts of edge cases -- in this case, if the Ring left the battlefield before the trigger resolves, the rules definitions for 'until' say that nothing happens at all (see the above post for the exact Comprehensive Rules citation).
I dunno. I do think it'd be pretty cool to play with, but I think it's dangerous giving that sort of unconditional removal to blue, even with the card advantage.
EDIT: Hey Earthquake doesn't hit flying creatures. Okay, other X-burn spells that hit creatures and players.
I also suggest making it sorcery-speed, for things like the following situation: you control one each of Bear Fold and Bird Fold attached to papers. I have a hand with 50 copies of Shredding Winds and infinite mana. However, I will never be able to destroy the Bird Fold; every time I cast a Wind, you switch in response and the spell fizzles; if you cast another one in response, I switch again in response, fizzle it, then switch back; and so on.
I dunno. Maybe these changes take away from your goal for the mechanic; that said, the mechanical child of banding and the Flagbearer mechanic at common is 1) anachronistic and probably no longer accepted under NWO due to board state and mechanical complexity, and 2) probably really weird to play with in some relatively common edge cases -- it's new, but it's weird and probably confusing/not straightforward.
Also, the whole 'discard and put into play' mechanic is weird too, but I concede I don't have a better suggestion and that it, at least, makes sense and doesn't have too many edge cases I can think of, besides eg letting Tormod's Crypt counter your spell but not actual Counterspell.
Anyway: that's a lot of mechanical nitpicks. Flavorfully, I think it's a very cool and wacky mechanic, and I certainly think there's room for designing some cool cards with it, so props on all those points.
Note that the counter-negation rule still applies to all permanents, though, not just creatures.
All creatures. Even if Nexus has a +1/+1 counter on it, that does not mean it has toughness or that it's a creature. Toxic Deluge will not do anything to something that's not a creature. So, assuming Nexus is a land and not a creature at the time (aka you didn't activate its ability that turn prior to your opponent casting Deluge) -- nothing happens, because Deluge applies to creatures and Nexus isn't one.
On the other hand, if Nexus is a creature (say, for instance, you activated it on your opponent's upkeep, and they cast Deluge in their main phase): then the above state-based action applies. Immediately following Deluge resolving, the game looks around, realizes that Nexus is a creature that now has <0 toughness, and destroys it, just how you'd expect it to do to any other 1/1 with a -1/-1 counter on it.
Now, here's a hypothetical scenario: you activate Inkmoth's ability, making it a 1/1 until end of turn. You control a couple of Glorious Anthems, meaning that Nexus is actually a 3/3 or something. Your opponent casts Black Sun's Zenith for 1, putting a -1/-1 counter on Nexus -- making it a 2/2. The turn ends, and Nexus reverts to being a land. Your opponent casts Cleanfall, destroying your Anthems. What happens?
Well, Nexus is a land with a -1/-1 counter on it. The counter doesn't just go away when Nexus stops being a creature; it just doesn't do anything, because Nexus isn't a creature and so the counter has no built-in effect on it (that is, the above rule only applies to creatures). And that's why, incidentally, a bunch of the rules in the comp rules regarding +1/+1 counters refer to 'permanent's with +1/+1 counters on them -- because you can't be sure it's a creature.
Note, though, that if you then chose to activate the ability and make Nexus a creature, the counter would suddenly have something to do again, Nexus would be a 0/0 creature, and it would die just as before. Note that the above extended example gets weirder if you use, eg, Giant Growth instead of Anthems, because I don't remember how end-of-turn effects work here (whether Nexus becomes a land or loses its toughness boost first) -- but luckily you didn't ask that and probably won't run into any time soon.
Lorwyn art is usually awesome, but is often thematically incomprehensible. Primalcrux might be a case of the opposite problem: you know the thematic material (wood elemental!), you just can't understand any other aspect of the art.
If I hazard a guess, I would say it's some sort of antlered beast -- probably a moose deer et al -- the two 3-pronged clusters are legs (unusually widely placed), and there's also some random wood sticking out above the left(rel to beast, our right) leg.
I'm seeing many cards from Kamigawa in your future.