msem-instigator

Flying
Whenever you cast a spell, draw a card, then put a +1/+1 counter on Maven of Perspective.

Defender, flying
Menagerie — As long as there are five or more creature types among creatures you control, Old-Rune Sentinel can attack as though it didn't have defender.

Flying, lifelink
Pay 5 life: Put target permanent card in a graveyard onto the battlefield under your control.

Vigilance, haste
At the beginning of each player's upkeep, if that player has the lowest life total or is tied for the lowest life total, they gain control of Protector of the Innocent.

Trample

Flying, vigilance, lifelink
During each of your turns, you may cast a multicolored spell from your graveyard.

{3}, {T}: Draw a card.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Concord — This spell costs {4} less to cast if there are four or more card types among permanents you control.
Vigilance, trample, lifelink, haste

Whenever Skeigr, Skhorvall Flagship attacks, it deals 3 damage divided as you choose among one, two, or three targets.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Ship Vehicle becomes an artifact creature until end of turn.)

Flying
Tap an artifact you control, a creature you control, and an enchantment you control: Return Stonecut Lammasu from your graveyard to your hand. Activate only as a sorcery.

This spell costs {1} less to cast for each creature you control that's in a pack. (Two or more creatures you control with equal power are in a pack.)

Whenever The Wicker Lord or another Scarecrow you control enters, create a 1/1 black Bird creature token with flying for each Scarecrow you control.
{4}, Sacrifice a Scarecrow: Return target artifact card from your graveyard to the battlefield.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Towering Wickerman can't be blocked by creatures with power 2 or less.
Whenever a creature merges with Towering Wickerman, put two +1/+1 counters on it.

Flying
Whenever a nontoken, noncreature, nonland permanent you control enters, create a token that's a copy of that permanent except it has no mana cost and it isn't legendary.

Flying
{2}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{W}{U}{B}{R}{G}: Search your library for a card, exile it, then shuffle. Until the end of your next turn, you may play that card.

Flying
You may cast enchantment spells from your graveyard.
Whenever an enchantment you control enters, draw a card.

Flying
When Sha Long enters, each player chooses an artifact they control, then sacrifices the rest. If they don't control an artifact, they may return an artifact card from their graveyard to the battlefield. Repeat this process for creatures, enchantments, and planeswalkers.

Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Atuum Serpent enters, if tribute was paid, it gains defender. (This effect lasts indefinitely.)

This spell costs {1} less to cast for each artifact and/or enchantment you control.

{6}{U}: Brume Trench-Thrasher can't be blocked this turn. This ability costs {1} less to activate for each instant and sorcery card you own in exile and in your graveyard.

Hexproof

Embellish {6}{U} (If you cast this spell for {6}{U}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
Whenever you attack, return any number of nonland permanents with different controllers and mana value less than or equal to the number of artifacts you control to their owners' hands.

Lionize {1}{U} ({1}{U}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
Hexproof

This spell costs {1} less to cast for each spell you cast this turn.
When Jidai Serpent enters, draw two cards.

{X}{U}{U}: Marine Monster can't be blocked by creatures with mana value X or less this turn.