Cards like Chronic Flooding, Pilfered Plans, Disrupt, and Psychic Drain are just not very good. You're spending a lot of cards and mana just to mill yourself slowly, without interacting with what the opponent is doing. Milling is also not good until you have a Lab Man out, otherwise you might just mill all your Lab Maniacs away and have no win condition! It's better to have cards that both interact with the opponent (or provide defense) and advance your gameplan (find Lab Man or mill yourself).
Drift of Phantasms and Stinkweed Imp are good, as already mentioned. Drift can either block OR find Lab Maniac, so it has 2 purposes. Stinkweed Imp can block and kill things and also mill you, so again it does 2 things. That's better than running a card that just mills you and does nothing else.
For a draw spell, Forbidden Alchemy is great at both digging through your library and milling you! And you can flashback copies you milled or cast. Fact or Fiction is great too. These spells will help you dig through your library to find the cards you want more efficiently. I would still run Opt because it lets you win immediately when you have no library, but Forbidden Alchemy and Fact or Fiction are much better than Pilfered Plans and some other cards.
Nephalia Drownyard is a reusable mill card you can fit into your manabase. You don't have to waste a spell slot on it. If you have extra mana and nothing else to do, you can use Drownyard to mill.
You want a way to return Lab Maniacs that were killed or milled. Dread Return is one way, but it is kind of combo-y and makes you suicide your own board. It's not so good if you don't plan to win that very turn. Corpse Churn is one way you can both mill yourself and bring back any Lab Maniacs you accidentally milled away. Liliana, Death's Majesty is another card that can both mill you and return any dead Lab Maniacs or walls. It also makes blockers and wipes the board, but it may be out of your budget.
Phenax, God of Deception works well to mill players when you're playing a Defender deck! You can also switch to milling the opponent if you want. It's a great win condition.
This card used to be a lot weaker when printed (although still a Standard Tier 1 deck finisher), because Vampires were midrange.
Nowadays there are so many things that make 1/1 Vampire tokens, including a Commander that makes them from the Command Zone, that your vampire count can get very high! Even turn 4 Call to the Feast into turn 5 Bloodwitch is already an Exsanguinate for 4 tacked onto a 4/4 flying body with protection.
"At this point"? Their priorities seemed obvious years ago after Modern became a thing. The writing was really on the wall when SCG and GPs switched their events to Standard/Modern and dropped Legacy to a minimal number of events each year.
R2R block was the last time they really made an attempt to throw bones to the Legacy community in a new Standard block. As far as WOTC is concerned, Legacy is like another Casual format and "Eternal" means "Commander".
That's a good approach to capture flavor at least! You can always fill it out with other cards from the guild to help the deck run more smoothly. For example, any Boros deck is immediately better with Lightning Helix. Skyknight Legionnaire is a classic too.
How does your deck perform? What's your playgroup meta like? Can you stay alive against efficient aggro swarms? Can you grind out against midrange decks with a lot of 2-for-1 creatures and/or recursion? Decks with many artifacts and enchantments? What are the deck's good and bad matchups?
On the surface there are some things I'd have questions about. But I tune control decks after testing them, because draw-go is about beating what your opponent does more than anything else. The best test is seeing if it does that or where it falls short. In a deck of answers, the best answers depend on what threats you're facing.
Anyway, based on just looking at the list and not playing it, this is what I see...
I notice you have 0 ways to actually kill noncreature permanents and just 2 ways to bounce them (tap-out sorcery or miracle, both of which have suboptimal timing). Do you not face many dangerous noncreatures? Or are you able to counter or bounce+counter them all with only 4 hard counters? A resolved Planeswalker or Phyrexian Arena or other card advantage or recursion engine might get out of hand.
As for creatures, you have a lot of bounce but only 6 ways to actually kill creatures (4 spot removal, 2 sweepers), all of which still leave bears behind. Those cards are great at neutralizing fatties and utility creatures with powerful abilities. But if the opponent is just swarming you out with aggro, those bears still hurt your life total. You won't have blockers or much lifegain. Has it been a problem?
You have a lot more bounce, which helps slow them down. But bounce isn't a permanent answer. If they are playing low curve, they might dump their hand again pretty easily, putting the pressure right back on. If they are playing creatures with good ETB/LTB abiliies, bouncing them or turning them to pigs might still leave them ahead in value. Sure you can counter some, but you won't counter everything with 4 Counterspell + 4 Condescend.
I think some hard sweepers (e.g. Nev Disk, Oblivion Stone) would be better than Curse of the Swine. It would answer both the noncreatures and the swarms without risking you get beat down by bears before you untap. You could even run artifact recursion (e.g. Buried Ruin) to get back your sweepers when you need them.
Brainstorm is weaker without shuffle effects. What about something like Accumulated Knowledge or Impulse? AK actually puts you ahead in cards eventually, unlike Brainstorm or Ponder. The old draw-go decks got ahead by being able to casting Counterspell/spot removal and following it up with cheap card draw at EOT.
Condescend can be an issue when you don't have a ramp deck. If you're tapping 7 mana to counter a threat lategame, you don't have mana open to draw cards or control the board. What about Rune Snag, Dismiss, Dissolve, or Exclude? There are a few options that both counter + draw/scry. Or you can choose one with Supreme Will.
The Zenith is really mana-hungry. Below 8 mana, it's trumped by other draw spells. It really shines in the lategame. You don't really have a mana engine and only have 22 lands, so even with card draw you may not hit land drops every single turn. Is one enough? Maybe the other should be a cheaper draw spell, or something that both draws cards and does something else (e.g. Confirm Suspicions)?
Welcome to MTGS. It's a good try for a first deck.
When building a deck, you want to try to put together cards that serve a similar theme and strategy.
For example, you have Scute Mob but only 19 lands. With so few lands, it will be very hard to get enough lands for Scute Mob's ability to work, so Scute Mob does not really fit into this deck. You have artifacts to help increase your mana but they do not increase your land count, so it does not help Scute Mob. The Mob is better in a different type of deck.
Invisible Stalker is a very fun card to kill people with, but it is also begging to be made bigger with Auras and Equipment. Because it is hexproof, it will not die easily, so it is safe to use other cards to make it bigger. Trepanation Blade is not very effective. Cards like Behemoth Sledge, Armadillo Cloak, and Invocation of Saint Traf are much better at making Invisible Stalker into a dangerous threat! You should try running something like that (or even Elephant Guide) instead of Trepanation Blade.
I don't understand what Bioshift is doing here. If you move the counter from Fleecemane Lion onto another creature, you don't make that other creature Monstrous or hexproof and indestructible. Bioshift only moves the +1/+1 counter, not any other abilities. You should probably remove it from your deck.
Fog is also not very good. It only protects you for one turn, but then you can still lose the next turn. Ghostly Prison is a much better strategy for defense. If you are playing multiplayer and want a Fog effect to surprise the opponent in case someone tries to kill you, at least play Moment's Peace, which is much better.
Why green? And why Zombie tokens instead of regular zombies? If you give some direction about how you want the deck to play out and what you want it to look like, that will help us with card suggestions.
Anyway, here is a deck that is green-black Zombie Madness and also makes zombie tokens via Zombie Infestation. It may be nothing like what you're looking for, but it's hard to tell what you want.
The deck works by discarding cards to Lotleth Troll (to grow him) or to Zombie Infestation (to make Zombies). Cards like Slitherhead, Gravecrawler, Asylum Visitor, Grave Scrabbler and Gisa's Bidding are all good to discard (assuming you have mana up to pay the madness cost).
Lord of the Undead and Grave Scrabbler help you return creatures back to your hand, keeping cards in your hand and helping you recover from removal. Asylum Visitor also helps you refill your hand faster as you dump cards into Zombie Infestation.
Gisa's Bidding works well with Zombie Infestation. Turn 2 Zombie Infestation. Turn 3 discard Gisa and some other card (e.g. Slitherhead or Gravecrawler) and pay 2B madness: you get 3 2/2 zombie tokens. That's pretty good value.
There's also the combo of Carrion Feeder + Gravecrawler to make a fat Carrion Feeder.
Slitherhead is probably better as Basking Rootwalla, but I left it as Slitherhead for the tribal synergy and flavor.
Yeah good point. I normally don't like expensive cards that don't affect the board this turn, but when you have "Destroy target creature", "Destroy all nonartifact creatures", and "create 2 dragons", maybe a tutor is worth it.
Original Ravnica also had some duds and some strong ones. Some mechanics synergize well with RTR guild mechanics. Others don't fit at all.
Selesnya - Convoke. It was also token-based, but about spamming lots of tokens on the board instead of populating a few fat tokens. Some Convoke spells are great. It just doesn't mesh well with Populate.
Izzet - Replicate. Never heard of it? That's because it's an even bigger dud than Overload. You could pay extra mana to make more copies of a spell. However most of the spells with it are terribad, to avoid anything broken like Storm was. The copies also don't trigger "when you cast an instant or sorcery", the other mechanic of this guild. The two mechanics have anti-synergy which is just awkward. It also has no synergy with Overload, the fixed version of Replicate. Wee Dragonauts and Izzet Guildmage are probably the only salavageable parts of this original guild.
Azorius - Forecast. You pay mana and reveal the card during your upkeep to get a marginal effect. It's very grindy long-term card advantage for slow control decks. The guild had some useful control pieces, but most Forecast cards were bad. Detain also slows down the game, which gives you time to forecast, but that's about all the synergy there is. However the cards do fit well for a slow control strategy.
Golgari - Dredge. Oops. This one broke the game. They meant it to be a grindy recursive engine to get back cards later in the game but didn't consider how easily the mechanic could be abused for self-mill shenanigans. You can dredge to put scavenge cards in the GY... or just dredge and win the game. Scavenge just isnt that good. Dredge is better with other stuff.
Rakdos - Hellbent. This was hyperaggro and rewarded you for dumping your hand fast. Some of it was card disadvantage and just bad, but some plays well with other aggro cards (like the Unleash mechanic!). New Rakdos should work with old Rakdoa for fast aggro.
Orzhov - Haunt. This let you reuse a spell or ETB effect after a creature died. It was a fun way to get extra card advantage. It doesn't fit that well with Extort, but you could try.
Gruul - Bloodthirst. This was the original set with it. +1/+1 counters if you dealt damage this turn. Good aggro. Bloodrush is also good aggro. It doesn't interact with Bloodthirst, but aggro + aggro = aggro so that seems good.
Simic - Graft. Also +1/+1 counters. It also gave abilities to creatures with +1/+1 counters, Graft plays very well with Evolve! Great synergy between blocks.
Dimir - mill. You could choose to mill X cards instead of deal X combat damage to opponent. This was a terrible terrible mechanic. Opponent starts with 60 cards and only 20 life. 1 life is not worth 1 card milled. It also has nothing to do with Cipher. The new mill cards are much better than the original Dimir mill.
Boros - Radiance. Copy effects for all creatures sharing a color. This has nothing to do with boros aggro or battalion. It's not a flavorful or synergistic mechanic. The guild was better at aggro - haste beaters and Lightning Helix. Those cards fit well into a Battalion deck, but not Radiance.
Blue is your best and deepest color, but there are also traps.
Slinn Voda is bad. I have never seen anyone play this card effectively. It's a vanilla 8/8 for 8, which is unplayable. The real value is at 10 mana, which any deck other than a real dedicated GU ramp deck will not pull off often enough.
Precognition Field is also bad. Too durdly. I've had bad experiences even with the better instant/sorcery saga that nets immediate value. This format is not good for a spells.dec.
I agree blue/red wizards is the way to go. You have enough Wizards to benefit from tribal bonuses, and Siege Gang is one of the best cards in the set.
White doesn't offer much, just Teferi and premium removal (which are splashable). No white bombs. No white synergies (can't go blue-white flyers, and not enough support for a Kwende double strike deck).
Skimming the above lists, I think blue/red lacks 23 playables so I would splash Teferi + 2 removals with a 7-7-3 manabase and call it a day. Teferi's minus ability is very relevant. He is not just card advantage. The splash gives you 3 cards that take bombs off the board!
I think your color choice was fine. Green is pretty shallow. Black has the most removal in a pool lacking in removal. I prefer removal to non-evasive fatties. But you left some powerful cards in the board and played a lot of vanilla. At the prerelease this is understandable. It wasn't obvious how slow and grindy this Sealed format would be at the time, making bears seem better than they are.
I would have played this. Still RB, because Scriptures and so much other good removal.
The other potential option is red-white first strike aggro, but I'd want a 2nd Kwende and a 2nd Jousting Lance to really push that plan. Blue just gives you a lot of power with the flyers and Clutches.
For Slimefoot, you probably want Necrogenesis (in Commander 2016!) and maybe Tukatongue Thallid (MM15). Since Slimefoot has a mana sink and commander tax is a thing, you probably want more ramp. You'll never be mana flooded.
For Tatyova, just play all the good ramp spells. Most of the big ones got reprints since M15 due to Commander popularity.
Then you have your choice of "big" spells. Kicker and Multikicker and mana sinks will probably shine. The hardest thing might be having enough interaction with the opponent, since these colors do not have good removal. Counters and bounce?
Wrath of God combos with Indestructible-granting effects.
One cute combo is to attack with Frontline Medic and 2 other creatures, then cast Wrath postcombat. Who said aggro decks can't Wrath?
You can also use Odric, Lunarch Marshal + any indestructible creature (e.g. Heliod, God of the Sun) to give your whole team indestructible. You don't even need to attack. Postcombat cast Wrath.
Cards like Chronic Flooding, Pilfered Plans, Disrupt, and Psychic Drain are just not very good. You're spending a lot of cards and mana just to mill yourself slowly, without interacting with what the opponent is doing. Milling is also not good until you have a Lab Man out, otherwise you might just mill all your Lab Maniacs away and have no win condition! It's better to have cards that both interact with the opponent (or provide defense) and advance your gameplan (find Lab Man or mill yourself).
Drift of Phantasms and Stinkweed Imp are good, as already mentioned. Drift can either block OR find Lab Maniac, so it has 2 purposes. Stinkweed Imp can block and kill things and also mill you, so again it does 2 things. That's better than running a card that just mills you and does nothing else.
For a draw spell, Forbidden Alchemy is great at both digging through your library and milling you! And you can flashback copies you milled or cast. Fact or Fiction is great too. These spells will help you dig through your library to find the cards you want more efficiently. I would still run Opt because it lets you win immediately when you have no library, but Forbidden Alchemy and Fact or Fiction are much better than Pilfered Plans and some other cards.
Nephalia Drownyard is a reusable mill card you can fit into your manabase. You don't have to waste a spell slot on it. If you have extra mana and nothing else to do, you can use Drownyard to mill.
You want a way to return Lab Maniacs that were killed or milled. Dread Return is one way, but it is kind of combo-y and makes you suicide your own board. It's not so good if you don't plan to win that very turn. Corpse Churn is one way you can both mill yourself and bring back any Lab Maniacs you accidentally milled away. Liliana, Death's Majesty is another card that can both mill you and return any dead Lab Maniacs or walls. It also makes blockers and wipes the board, but it may be out of your budget.
Phenax, God of Deception works well to mill players when you're playing a Defender deck! You can also switch to milling the opponent if you want. It's a great win condition.
Nowadays there are so many things that make 1/1 Vampire tokens, including a Commander that makes them from the Command Zone, that your vampire count can get very high! Even turn 4 Call to the Feast into turn 5 Bloodwitch is already an Exsanguinate for 4 tacked onto a 4/4 flying body with protection.
R2R block was the last time they really made an attempt to throw bones to the Legacy community in a new Standard block. As far as WOTC is concerned, Legacy is like another Casual format and "Eternal" means "Commander".
On the surface there are some things I'd have questions about. But I tune control decks after testing them, because draw-go is about beating what your opponent does more than anything else. The best test is seeing if it does that or where it falls short. In a deck of answers, the best answers depend on what threats you're facing.
Anyway, based on just looking at the list and not playing it, this is what I see...
I notice you have 0 ways to actually kill noncreature permanents and just 2 ways to bounce them (tap-out sorcery or miracle, both of which have suboptimal timing). Do you not face many dangerous noncreatures? Or are you able to counter or bounce+counter them all with only 4 hard counters? A resolved Planeswalker or Phyrexian Arena or other card advantage or recursion engine might get out of hand.
As for creatures, you have a lot of bounce but only 6 ways to actually kill creatures (4 spot removal, 2 sweepers), all of which still leave bears behind. Those cards are great at neutralizing fatties and utility creatures with powerful abilities. But if the opponent is just swarming you out with aggro, those bears still hurt your life total. You won't have blockers or much lifegain. Has it been a problem?
You have a lot more bounce, which helps slow them down. But bounce isn't a permanent answer. If they are playing low curve, they might dump their hand again pretty easily, putting the pressure right back on. If they are playing creatures with good ETB/LTB abiliies, bouncing them or turning them to pigs might still leave them ahead in value. Sure you can counter some, but you won't counter everything with 4 Counterspell + 4 Condescend.
I think some hard sweepers (e.g. Nev Disk, Oblivion Stone) would be better than Curse of the Swine. It would answer both the noncreatures and the swarms without risking you get beat down by bears before you untap. You could even run artifact recursion (e.g. Buried Ruin) to get back your sweepers when you need them.
Brainstorm is weaker without shuffle effects. What about something like Accumulated Knowledge or Impulse? AK actually puts you ahead in cards eventually, unlike Brainstorm or Ponder. The old draw-go decks got ahead by being able to casting Counterspell/spot removal and following it up with cheap card draw at EOT.
Condescend can be an issue when you don't have a ramp deck. If you're tapping 7 mana to counter a threat lategame, you don't have mana open to draw cards or control the board. What about Rune Snag, Dismiss, Dissolve, or Exclude? There are a few options that both counter + draw/scry. Or you can choose one with Supreme Will.
The Zenith is really mana-hungry. Below 8 mana, it's trumped by other draw spells. It really shines in the lategame. You don't really have a mana engine and only have 22 lands, so even with card draw you may not hit land drops every single turn. Is one enough? Maybe the other should be a cheaper draw spell, or something that both draws cards and does something else (e.g. Confirm Suspicions)?
But those aren't the only 2 decks possible. GBw can have more removal.
1 Llanowar Elves
1 Shanna, Sisay's Legacy
1 Sporecrown Thallid
2 Saproling Migration
2 Yavimaya Sapherd
2 Slimefoot, the Stowaway
1 Skittering Surveyor
1 Josu Vess, Lich Knight
1 Shalai, Voice of Plenty
1 Thallid Omnivore
2 Spore Swarm
1 Vicious Offering
1 Gideon's Reproach
1 Ancient Animus
1 Broken Bond
2 Eviscerate
1 Icy Manipulator
1 The Eldest Reborn
//Buffs: 3
2 Song of Freyalise
1 Forebear's Blade
//Lands: 18
9 Forest
6 Swamp
3 Plains
2 Pierce the Sky
2 Divest
1 Sylvan Awakening
1 Windgrace Acolyte
1 Traxos, Scourge of Kroog
1 Wild Onslaught
Or you could play RB to play more of your bombs and removal at once
2 Shivan Fire
1 Vicious Offering
1 Icy Manipulator
2 Eviscerate
1 Fiery Intervention
1 The Eldest Reborn
1 Jaya's Immolating Inferno
//Creatures: 15
1 Voltaic Servant
2 Ghitu Chronicler
1 Bloodstone Goblin
1 Dread Shade
1 Keldon Overseer
1 Skittering Surveyor
1 Valduk, Keeper of the Flame
1 Squee, the Immortal
1 Josu Vess, Lich Knight
1 Verix Bladewing
1 Traxos, Scourge of Kroog
2 Windgrace Acolyte
1 Forebear's Blade
1 Soul Salvage
//Lands: 19
10 Swamp
9 Mountain
1 Goblin Barrage
1 Soul Salvage
1 Haphazard Bombardment
1 Radiating Lightning
1 Feral Abomination
1 Windgrace Acolyte
Or Red-White Equipment
1 Voltaic Servant
2 Mesa Unicorn
2 Serra Disciple
1 D'Avenant Trapper
1 Squee, the Immoral
1 Valduk, Keeper of the Flame
1 Traxos, Scourge of Kroog
1 Kwende, Pride of Femeref
1 Shalai, Voice of Plenty
1 Verix Bladewing
1 Baird, Steward of Argive
1 Serra Angel
1 Pardic Wanderer
1 Bloodtallow Candle
2 Shivan Fire
1 Gideon's Reproach
1 Icy Manipulator
1 Fiery Intervention
1 Jaya's Immolating Inferno
//Buffs: 4
1 Short Sword
1 Jousting Lance
1 Forebear's Blade
1 On Serra's Wings
//Lands: 18
9 Mountain
9 Plains
1 Goblin Barrage
1 Haphazard Bombardment
1 Call the Cavalry
1 Dub
1 Radiating Lightning
2 Adamant Will
When building a deck, you want to try to put together cards that serve a similar theme and strategy.
For example, you have Scute Mob but only 19 lands. With so few lands, it will be very hard to get enough lands for Scute Mob's ability to work, so Scute Mob does not really fit into this deck. You have artifacts to help increase your mana but they do not increase your land count, so it does not help Scute Mob. The Mob is better in a different type of deck.
Invisible Stalker is a very fun card to kill people with, but it is also begging to be made bigger with Auras and Equipment. Because it is hexproof, it will not die easily, so it is safe to use other cards to make it bigger. Trepanation Blade is not very effective. Cards like Behemoth Sledge, Armadillo Cloak, and Invocation of Saint Traf are much better at making Invisible Stalker into a dangerous threat! You should try running something like that (or even Elephant Guide) instead of Trepanation Blade.
I don't understand what Bioshift is doing here. If you move the counter from Fleecemane Lion onto another creature, you don't make that other creature Monstrous or hexproof and indestructible. Bioshift only moves the +1/+1 counter, not any other abilities. You should probably remove it from your deck.
Fog is also not very good. It only protects you for one turn, but then you can still lose the next turn. Ghostly Prison is a much better strategy for defense. If you are playing multiplayer and want a Fog effect to surprise the opponent in case someone tries to kill you, at least play Moment's Peace, which is much better.
Rootborn Defenses is not good here because you have nothing to populate. If you want a card to protect your creatures, consider Selfless Spirit, Dauntless Escort or Make a Stand.
Anyway, here is a deck that is green-black Zombie Madness and also makes zombie tokens via Zombie Infestation. It may be nothing like what you're looking for, but it's hard to tell what you want.
4 Slitherhead
4 Gravecrawler
4 Carrion Feeder
4 Lotleth Troll
4 Asylum Visitor
3 Grave Scrabbler
3 Lord of the Undead
2 Skinrender
4 Zombie Infestation
//Spells: 6
4 Cast Down
2 Gisa's Bidding
//Lands: 22
4 Golgari Guildgate
4 Woodland Cemetery
10 Swamp
4 Forest
The deck works by discarding cards to Lotleth Troll (to grow him) or to Zombie Infestation (to make Zombies). Cards like Slitherhead, Gravecrawler, Asylum Visitor, Grave Scrabbler and Gisa's Bidding are all good to discard (assuming you have mana up to pay the madness cost).
Lord of the Undead and Grave Scrabbler help you return creatures back to your hand, keeping cards in your hand and helping you recover from removal. Asylum Visitor also helps you refill your hand faster as you dump cards into Zombie Infestation.
Gisa's Bidding works well with Zombie Infestation. Turn 2 Zombie Infestation. Turn 3 discard Gisa and some other card (e.g. Slitherhead or Gravecrawler) and pay 2B madness: you get 3 2/2 zombie tokens. That's pretty good value.
There's also the combo of Carrion Feeder + Gravecrawler to make a fat Carrion Feeder.
Slitherhead is probably better as Basking Rootwalla, but I left it as Slitherhead for the tribal synergy and flavor.
Selesnya - Convoke. It was also token-based, but about spamming lots of tokens on the board instead of populating a few fat tokens. Some Convoke spells are great. It just doesn't mesh well with Populate.
Izzet - Replicate. Never heard of it? That's because it's an even bigger dud than Overload. You could pay extra mana to make more copies of a spell. However most of the spells with it are terribad, to avoid anything broken like Storm was. The copies also don't trigger "when you cast an instant or sorcery", the other mechanic of this guild. The two mechanics have anti-synergy which is just awkward. It also has no synergy with Overload, the fixed version of Replicate. Wee Dragonauts and Izzet Guildmage are probably the only salavageable parts of this original guild.
Azorius - Forecast. You pay mana and reveal the card during your upkeep to get a marginal effect. It's very grindy long-term card advantage for slow control decks. The guild had some useful control pieces, but most Forecast cards were bad. Detain also slows down the game, which gives you time to forecast, but that's about all the synergy there is. However the cards do fit well for a slow control strategy.
Golgari - Dredge. Oops. This one broke the game. They meant it to be a grindy recursive engine to get back cards later in the game but didn't consider how easily the mechanic could be abused for self-mill shenanigans. You can dredge to put scavenge cards in the GY... or just dredge and win the game. Scavenge just isnt that good. Dredge is better with other stuff.
Rakdos - Hellbent. This was hyperaggro and rewarded you for dumping your hand fast. Some of it was card disadvantage and just bad, but some plays well with other aggro cards (like the Unleash mechanic!). New Rakdos should work with old Rakdoa for fast aggro.
Orzhov - Haunt. This let you reuse a spell or ETB effect after a creature died. It was a fun way to get extra card advantage. It doesn't fit that well with Extort, but you could try.
Gruul - Bloodthirst. This was the original set with it. +1/+1 counters if you dealt damage this turn. Good aggro. Bloodrush is also good aggro. It doesn't interact with Bloodthirst, but aggro + aggro = aggro so that seems good.
Simic - Graft. Also +1/+1 counters. It also gave abilities to creatures with +1/+1 counters, Graft plays very well with Evolve! Great synergy between blocks.
Dimir - mill. You could choose to mill X cards instead of deal X combat damage to opponent. This was a terrible terrible mechanic. Opponent starts with 60 cards and only 20 life. 1 life is not worth 1 card milled. It also has nothing to do with Cipher. The new mill cards are much better than the original Dimir mill.
Boros - Radiance. Copy effects for all creatures sharing a color. This has nothing to do with boros aggro or battalion. It's not a flavorful or synergistic mechanic. The guild was better at aggro - haste beaters and Lightning Helix. Those cards fit well into a Battalion deck, but not Radiance.
Slinn Voda is bad. I have never seen anyone play this card effectively. It's a vanilla 8/8 for 8, which is unplayable. The real value is at 10 mana, which any deck other than a real dedicated GU ramp deck will not pull off often enough.
Precognition Field is also bad. Too durdly. I've had bad experiences even with the better instant/sorcery saga that nets immediate value. This format is not good for a spells.dec.
I agree blue/red wizards is the way to go. You have enough Wizards to benefit from tribal bonuses, and Siege Gang is one of the best cards in the set.
White doesn't offer much, just Teferi and premium removal (which are splashable). No white bombs. No white synergies (can't go blue-white flyers, and not enough support for a Kwende double strike deck).
Skimming the above lists, I think blue/red lacks 23 playables so I would splash Teferi + 2 removals with a 7-7-3 manabase and call it a day. Teferi's minus ability is very relevant. He is not just card advantage. The splash gives you 3 cards that take bombs off the board!
I would have played this. Still RB, because Scriptures and so much other good removal.
1 Keldon Warcaller
1 Bloodstone Goblin
1 Cabal Evangel
2 Keldon Overseer
1 Ghitu Journeymage
1 Valduk, Keeper of the Flame
1 Verix Bladewing
1 Keldon Raider
1 Traxos, Scourge of Kroog
1 Rampaging Cyclops
2 Windgrace Acolyte
1 Guardians of Koilos
1 Mishra's Self-Replicator
1 Fungal Infection
1 Bloodtallow Candle
1 Vicious Offering
1 Forebear's Blade
1 Helm of the Host
1 Eviscerate
1 Phyrexian Scriptures
1 The Eldest Reborn
//Lands:
1 Zhalfrin Void
8 Mountain
8 Swamp
1 Soul Salvage
1 Cabal Evangel
1 Whisper, Blood Liturgist
1 Yawgmoth's Vile Offering
Historic: 10
Replicator and Traxos should have sufficient support. Guardians has synergy with reusing Scriptures or Eldest Reborn to really wreck opponent's board.
You could maybe play Whisper, Blood Liturgist to have even more historic and more recursion, but the other 4 drops all seem like much better blockers.
1 Naban, Dean of Iteration
1 Vodalian Arcanist
1 Bloodstone Goblin
1 Keldon Warcaller
1 Ghitu Chronicler
1 Ghitu Journeymage
1 Valduk, Keeper of the Flame
1 Howling Golem
1 Academy Drake
1 Rampaging Cyclops
1 Verix Bladewing
3 Cloudreader Sphinx
1 Academy Journeymage
1 Cold-Water Snapper
1 Shivan Fire
1 Opt
1 Jousting Lance
1 Run Amok
1 Fight with Fire
1 Time of Ice
1 In Bolas's Clutches
//Lands: 17
1 Sulfur Falls
8 Island
8 Mountain
Curve:
1 - ss
2 - cccccss
3 - ccccs
4 - ccs
5 - cccc
6 - cs
The other potential option is red-white first strike aggro, but I'd want a 2nd Kwende and a 2nd Jousting Lance to really push that plan. Blue just gives you a lot of power with the flyers and Clutches.
For Slimefoot, you probably want Necrogenesis (in Commander 2016!) and maybe Tukatongue Thallid (MM15). Since Slimefoot has a mana sink and commander tax is a thing, you probably want more ramp. You'll never be mana flooded.
For Tatyova, just play all the good ramp spells. Most of the big ones got reprints since M15 due to Commander popularity.
Then you could also consider some built into creatures:
Then you have your choice of "big" spells. Kicker and Multikicker and mana sinks will probably shine. The hardest thing might be having enough interaction with the opponent, since these colors do not have good removal. Counters and bounce?
One cute combo is to attack with Frontline Medic and 2 other creatures, then cast Wrath postcombat. Who said aggro decks can't Wrath?
You can also use Odric, Lunarch Marshal + any indestructible creature (e.g. Heliod, God of the Sun) to give your whole team indestructible. You don't even need to attack. Postcombat cast Wrath.