msem-instigator

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

When Carrion Sculptor enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Return target creature card from your graveyard to your hand.
{1}{B}, Exile Carrion Sculptor from your graveyard: Create a tapped 2/2 black Zombie creature token.

Once each turn, when Vedu, the Deepdrinker enters or you attack with one or more Horrors, you may tap up to two target permanents. If Vedu isn't a token, put two stun counters on each of those permanents.
{2}{U}{U}, Discard Vedu: Create a token that's a copy of Vedu, the Deepdrinker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

{T}: Discard two cards. If you do, draw two cards.

When Biohazard enters, destroy all other nonland permanents with mana value X or less.
At the beginning of each end step, each opponent loses life equal to the number of cards they've drawn this turn plus the number of spells they've cast this turn.

Whenever another creature with power 4 or greater you control enters, you may draw a card.

When Colony Soldier enters, create a 1/1 green Insect creature token.

Whenever one or more creatures you control attack, create a 1/1 white Human Samurai creature token.

When Shapur, the Fifth Shah enters, exile target instant or sorcery card from your graveyard. Until end of turn, you may cast that card. If that spell would be put into a graveyard, exile it instead.
Monument {4}{R} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{3}{G}: Harmonic Recruit gets +2/+2 until end of turn. If you're in a renaissance, it gets +4/+4 until end of turn instead.

Flying
Whenever Planetary Reconnoiterer attacks, target creature you control gains flying until end of turn.

You may play an additional land this turn.
Draw a card.
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.)

{2}: Other creatures you control get +1/+0 until end of turn.
Whenever Sun-Crowned Flagship attacks, each attacking creature you control gains trample until end of turn.
Crew 7 (Tap any number of creatures you control with total power 7 or greater: This Vehicle becomes an artifact creature until end of turn.)

Whenever a land you control enters, add one mana of any color.
Whenever Enraged Fangwurm attacks, you may sacrifice a land. If you do, Enraged Fangwurm deals 2 damage to target player or planeswalker.

When Clairvoyant Mage enters, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Draw three cards. (Then exile this card. You may cast the creature later from exile.)

Legacy (You may play this side of this card only from your graveyard. Exile it if it would be put into a graveyard or not resolve.)
Volcano Sacrifice deals damage to target creature or planeswalker equal to the number of creature cards in your graveyard.

({T}: Add {B} or {G}.)
Duskwood Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Enchant creature
Enchanted creature can't attack or block.

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Creatures can't attack this turn. If this spell's tithe was paid, opponents can't cast spells this turn.

When Lunar Pact enters, target creature attacks during its controller's next combat if able.
Players can't untap more than two nonbasic permanents during their untap step.

Improve {W} ({W}: 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.)
Whenever one or more embattled creatures you control attack, create a 1/1 white Cleric creature token with lifelink. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Whenever Current Shaper perseveres, it deals 1 damage to each opponent. (A creature perseveres when it survives damage.)

Love Letters enters with X stamp counters on it.
Whenever one or more creatures you control deal combat damage to a player, you may remove a stamp counter from Love Letters. If you do, draw a card.

{T}: Create a Treasure token.
{W}{U}{B}{R}{G}: Until end of turn, Guardians of Kallian's Tomb becomes a 5/5 Ox artifact creature and gains trample and “Whenever this creature attacks, defending player sacrifices a permanent unless they have you draw two cards.”