msem-instigator

Flying
When Imposing Sphinx enters, exile target nonland permanent an opponent controls until Imposing Sphinx leaves the battlefield.
At the beginning of your end step, if you gained life this turn, you may exile Imposing Sphinx, then return it to the battlefield under your control.

Tizzanier Tidehunter can't be blocked as long as you control another Merfolk.

When Rakkiri Aspirant enters, if you control an embattled creature, exile the top card of your library. Until end of turn, you may play that card. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Enchant creature
As Legacy of Dawn Hill enters, choose a creature type.
Enchanted creature gets +2/+0, has first strike, and is the chosen type in addition to its other types.

{3}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)
When Shorecrash Octopus becomes monstrous, return target instant or sorcery card from your graveyard to your hand.

Scrollsnatcher can't block and can't be blocked.
Whenever Scrollsnatcher deals combat damage to a player, look at the top card of each library, then put any number of those cards into their owner's graveyards.

Flying, first strike, vigilance, trample, lifelink
{4}: Put a +1/+1 counter on Alin and Meva, Warqueens.

Deathwind Survivor's power and toughness are each equal to the number of enchantments you control.
Whenever an enchantment you control enters, put a +1/+1 counter on target creature.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Demolitionist Deviser dies, it deals damage equal to its power to any target.

Whenever a land you control enters or a land card is put into your graveyard from anywhere, create a 0/1 green Plant creature token.
{3}{G}{G}: Put a +1/+1 counter on each other creature you control.

As long as it's your turn, Rallying Rector has first strike.
Whenever Rallying Rector attacks, you may discard a card. If you do, search your library for a card named Rallying Rector, reveal it, put it into your hand, then shuffle.

When this creature enters, search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Arise {2}{W} ({2}{W}, Exile this from your graveyard as a sorcery: Create a black token copy of it that's also a Zombie and can't block.)

Dawn Hill Outskirts enters tapped unless you played it from exile.
{T}: Add {R} or {W}.

Dawn Without End deals damage to each opponent equal to the number of nonbasic lands they control.
Acquiesce (If you cast this spell from your hand, exile it as it resolves. When one or more creatures you control deal combat damage to an opponent, you may cast this card from exile without paying its mana cost.)

I, II — Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Discovery — {4}: You gain 2 life.

When Artificial Wayfinder enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Alley Hunter has lifelink as long as it's blocked by a marked creature.

Deathtouch
Whenever another creature you control dies, each opponent loses 1 life.
{2}{W}: Create a 1/1 colorless Servo artifact creature token.

{1}{W}, {T}, Sacrifice Prophet of Pacifism: Prevent all damage that would be dealt to players this turn.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

When Patrol Droid dies, if it attacked this turn, conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

{2}{W}, Exile Worldwise Ascetic from your graveyard: Create a green Aura enchantment token named Years of Experience attached to target creature. The token has enchant creature and “Enchanted creature gets +2/+2.” Activate only as a sorcery.

When Convocation Elder enters, create two 1/1 green Elf creature tokens.
{1}{G}, Discard Convocation Elder: Create a 1/1 green Elf creature token. Draw a card. Activate only as a sorcery.

{T}: Add {C}.
When Heavenly Temple enters, target creature gains flying until end of turn.
{2}: Return Heavenly Temple from the battlefield to its owner's hand.

Flying
Whenever DC-4 Cutie enters or attacks, choose target creature card with mana value 3 or less in your graveyard. You may cast it this turn.
Crew 2

At the beginning of your upkeep, discard a card and create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)