msem-instigator

Whenever a creature you control enters, Timid Thunderhorn gets +X/+X until end of turn, where X is that creature's power.

You may pay {1}{G} and tap an untapped Soldier you control rather than pay this spell's mana cost.
Put two +1/+1 counters on target creature. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Return target creature card from your graveyard to the battlefield, then destroy target creature an opponent controls that doesn't share a creature type with it.

Flying
Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Tireless Vulture enters, if tribute wasn't paid, each opponent loses 3 life. You gain life equal to the life lost this way.

Prowess
Whenever you cast an instant or sorcery spell, Tirenan Pyromancer deals 1 damage to each opponent.

When Titan of Lake Vasil enters, untap up to four target permanents.
{3}{U}: Draw a card.

Colossal 2—{6}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {6}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
When Titanic Fathomclaw's colossal ability puts one or more counters on it, return target instant or sorcery card from your graveyard to your hand.

First strike
Noncreature spells with mana value 4 or greater cost {1} more to cast.

When Titou Louoe, Bayou Shaman enters, create a blue Aura Curse enchantment token named Curse of Impotence attached to target player. The token has enchant player and “Creatures enchanted player controls get -1/-0.”

Until end of turn, target creature gets +1/+0 and gains “Whenever this creature is dealt damage, exile that many cards from the top of your library. Until end of turn, you may play those cards.”

Arm target creature you control. It deals damage equal to its power to any target. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Creatures with power 4 or greater can't attack or block unless their controller pays {2} for each of those creatures.

Whenever a creature you control attacks, you may sacrifice a Treasure. If you do, that creature can't be blocked this turn.

You may put cards with mana value 2 or less that permanents you control explore into your hand as though they were lands. (You won't get the counter if you do.)
Whenever Torch of Those Underfoot attacks, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Attacking creatures you control get +1/+0.
Mirage {2}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

As an additional cost to cast this spell, discard a card.
Draw two cards. Then if you cast another instant or sorcery spell this turn, draw a card.

Flying
Ward—{2}, Pay 2 life.
At the beginning of your end step, if a card was put into or left your graveyard this turn, put a +1/+1 counter on Tormentor of Graves.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
Crew 1 (Tap any number of creatures you control with total power 1 or greater: This Vehicle becomes an artifact creature until end of turn.)

Exile up to two target artifacts, creatures, and/or enchantments you control. Return those cards to the battlefield under your control at the beginning of the next end step.

{G}, {T}: Add one mana of any color. When a creature enters this turn, if that mana was spent to cast it, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Whenever Tortle Veteran or another Turtle you control enters, that creature explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Target creature gets +1/+0 until end of turn. Add {R}.

Target player gets a poison counter.
Draw a card.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, target player discards a card.

Vigilance, reach
When this creature transforms into Towering Alpha, return target card from your graveyard to your hand.
At the beginning of your end step, if Towering Alpha didn't attack this turn, transform it.