msem-instigator

Whenever a creature you control dies, Twilight Blade deals 1 damage to each opponent and you gain 1 life.

When Twisted Predator dies, you draw a card and you lose 1 life.

Tzelin of the Demon Realm can't block.
Whenever a Demon you control enters, you may pay {B}. If you do, return Tzelin from your graveyard to the battlefield with a +1/+1 counter on it.

If a creature card would be put into an opponent's graveyard from anywhere, instead exile it, then copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)

Flash
If a card or token would be put into an opponent's graveyard from anywhere, exile it instead.

At the beginning of your upkeep, reveal the top card of your library. If it has the same name as a card in your graveyard, put the revealed card into your hand. Otherwise, put it into your graveyard.

When Unmasker of Fate's Design enters, look at target player's hand. Choose a nonland card from it and exile that card with a puzzle counter on it. As long as that card has a puzzle counter on it, that player may pay {2} and 1 life at any time. If they do, return the exiled card to their hand.

Glitch—Sacrifice a creature. (Remove one [restriction] for each time you pay the glitch cost.)
When Unshackled Revolutionary enters, you may destroy target creature an opponent controls [with mana value 3 or less]. [You lose 3 life.]

When Vile Weavers enters, if you control an enchantment, target player loses 3 life.

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
{2}{B}: Choose a counter on target permanent or player. Give that permanent or player another counter of that kind.

Voidtouched Nightblade can't block.
Simulacrum (When this creature dies, exile it from your graveyard. If you do, create a token that is a copy of it except it is a colorless 1/1 Crystal Elf Rogue artifact creature.)

At the beginning of your upkeep, each player discards a card.
Whenever Waking Watcher attacks, if defending player has no cards in hand, it gets +3/+3 and gains menace until end of turn.

When Weeping Yaoguai enters, create a 1/1 colorless Spirit creature token.
Scavenge {3}{B} ({3}{B}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Flash
When Wormwood's Agent dies, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Menace
Yaran's Enforcer gets +1/+1 as long as you foretold a card this turn.
Yaran's Enforcer gets +1/+1 as long as you cast a foretold spell this turn.

Whenever a nontoken creature you control dies, create a 1/1 black Skeleton creature token.

Whenever Yri, the Daring Blade and exactly one other creature attack, Yri and that creature can't be blocked by creatures with mana value 3 or less this turn.

Non-Human creatures you control get +1/+0.

Ainok Alpha can't be blocked by more than one creature.
Other Hounds you control get +1/+1 and can't be blocked by more than one creature.

Menace
Whenever Akoum Trailblazer deals combat damage to a player, you may discard a card. If you do, draw a card.
Whenever you discard a card, you may pay {R}. If you do, create a 1/1 red Goblin creature token.

Flash
When Ancestral Warlord enters, it deals 1 damage to each blocking creature.

{1}{R}: Aravant Throatcutter and up to one other target Pirate or Rogue you control each get +1/+0 until end of turn.

Whenever Archlegislator attacks, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
{3}{R}{R}, {T}, Sacrifice an Aura: Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, Artisan of Brutality gets +2/+0 and gains first strike until end of turn.

Ash Freebooter has first strike as long as it's attacking.
When Ash Freebooter enters, you may discard a card. If you do, draw a card.