msem-instigator

Haste
Whenever Abominable Auteur attacks, you may return target creature card with mana value 3 or less from your graveyard to the battlefield. If that card's mana value was 1 or less, it enters tapped and attacking.

Transcend (Activate as a sorcery to gain the next type and a +1/+1 counter.)
Vigilance, trample
{G}{W}: Demon — Abwad Kahroba gains “At the beginning of combat on your turn, you may put a +1/+1 counter on another target creature.”
{X}{G}{W}: Elder — Create X 2/1 black Horror creature tokens. You gain X life.

Deathtouch
Abyss Surger enters with X +1/+1 counters on it, where X is the greatest power among creature cards in your graveyard.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Abyssal Accuser must be blocked if able.

Flying
{2}{W}, Exile a non-Spirit creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

When Acolyte of Griselbrand dies, you draw a card and you lose 1 life.
Foreshadow {4}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Flying
Whenever you draw a card, put a +1/+1 counter on Acolyte of Life.
Remove two counters from Acolyte of Life: It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
As you choose targets for an instant or sorcery spell, choose up to one additional target.
At the beginning of combat on your turn, gain control of another target creature until end of turn. Untap that creature. It gains haste until end of turn.

{G}: Tap Adaptive Troll. It gains indestructible until end of turn.
At the beginning of each upkeep, if Adaptive Troll was dealt lethal damage last turn, put a counter of your choice on it from among vigilance, deathtouch, reach, trample, and +1/+1.

Flying
Whenever another creature you control enters, Adavene, Dean of the Arts deals 1 damage to each opponent.
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield.

Deathtouch
Whenever Addermark Eviscerator deals combat damage to a player, draw a card.
At the beginning of your end step, if Addermark Eviscerator didn't attack this turn, transform it.

{T}: Adept Fisherman voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Adept Fisherman phases in, you gain 2 life.

Whenever Adept Lieutenant attacks, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{1}, Sacrifice an Idol: Put a +1/+1 counter on Adept Lieutenant.

Prowess
When Adept of Signals enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Tokens you control have “{2}, {T}: Sacrifice this token: Draw a card.”

Haste
Whenever two or more creatures you control deal combat damage to a player, tap those creatures, then gain control of target creature you don't control until end of turn. Untap that creature. It gains haste until end of turn. After this phase, there's an additional combat phase.

Menace
Whenever a creature an opponent controls dies, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

{1}{U}: Aeon's Hand Cutthroat can't be blocked this turn.

Flying
At the beginning of your end step, untap another target creature you control.

({T}: Add {U}.)
Aerie's Pillar enters tapped.
Flying
{2}{U}{U}: Aerie's Pillar becomes a creature in addition to its other types until end of turn.

Flying
{2/U}{2/U}: Exile Aeriform Remnant. Return it to the battlefield under its owner's control at the beginning of the next end step.

Prowess
At the beginning of each end step, if you cast a multicolor spell or two spells with different colors this turn, each opponent sacrifices a permanent.

Flash
If you would upgrade a creature you control, you may put a +1/+1 counter on it instead.
{3}{U}: Put a +1/+1 counter on Affluent Cetanthrope and draw a card.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Once each turn, when one or more counters are put on a permanent you control, create a 1/1 colorless Human creature token.
Whenever you attack with three or more creatures, destroy up to one target artifact or enchantment.

Deception {1}{B}
When Aguri, Shadow of Doubt enters, target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Whenever one or more counters are put on a permanent you control for the first time each turn, create that many 1/1 green Squirrel creature tokens.
{1}{G}{W}, {T}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)