msem-instigator

Trample
When Shigurei, the Floodbringer enters, up to three target permanents become colorless Island lands.

Shimmering Seadragon gets +1/+0 and can't be blocked as long as you control a legendary creature.

When Shojiro, the Wavewaker enters, submerge up to eight target creatures your opponents control. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

Flying
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

If a creature entering the battlefield under your control causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
{1}{U}, {T}: Exile another target creature. Return it to the battlefield under its owner's control at the beginning of the next end step.

Create two 1/1 blue Bird creature tokens with flying and “When this creature dies, draw a card.”

When Undead Archivist enters, return target instant or sorcery card from your graveyard to your hand.
Revive {5}{U} ({5}{U}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Target creature gets -9/-0 until end of turn. 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.”)

Return target creature to its owner's hand. That player can't cast spells with the same name as that creature during their next turn.

Invigorate 1, then untap each creature you control with a +1/+1 counter on it. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

When Warrior's Perspective enters, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it becomes tapped, you may draw a card. If you do, discard a card.

Create two Idol tokens, then counter target spell unless its controller pays {1} for each Idol you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Flying
Welkin Tern can block only creatures with flying.

Whenever Whitepeak Channeler deals combat damage to a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

Flying
Whenever Yawning Crane deals combat damage to an opponent, target tapped creature that player controls doesn't untap during its controller's next untap step.

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.”)

Target opponent loses 2 life and you gain 2 life. If you control a Wizard, instead that player loses 4 life and you gain 4 life.

Target creature gets -3/-2 until end of turn.

As an additional cost to cast this spell, sacrifice a creature.
All creatures get -X/-X until end of turn, where X is the sacrificed creature's power.

{B}, Sacrifice another creature: Deranged Apothecary gains indestructible until end of turn.

As an additional cost to cast this spell, sacrifice a creature.
Create a 5/5 black Demon creature token with flying. You lose 2 life.

When Diseased Prophet enters, each opponent loses 1 life.
Revive {B} ({B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Cast this spell only if each graveyard has a creature card in it.
Each player puts a creature card in their graveyard of an opponent's choice onto the battlefield.

Target player discards two cards.
Ferocious — That player discards two cards at random instead if you control a creature with power 4 or greater.

Menace
Whenever Dragon's Twisted Shadow attacks and isn't blocked, it gets +4/+0 until end of turn.