msem-instigator

Convoke (Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Protection from noncreatures
When The Magistrate enters, judge each creature that convoked it. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

When The Marrow Lord enters, search your library for a card with arise, put that card into your graveyard, then shuffle.
Whenever you activate an ability of a card in your graveyard or a creature you control enters from a graveyard, this creature deals 1 damage to any target.

Deathtouch
Whenever you lose life, you may cast target black noncreature card in your graveyard this turn. If it would be put into a graveyard from anywhere this turn, exile it instead.
Whenever you gain life for the first time each turn, create a 1/1 black Actor creature token.

As The Mistake enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.
Unveil {5} ({5}: Transform this. Unveil only as a sorcery.)

When The Raven Queen of Fretport enters, put a -1/-1 counter on each of any number of target creatures.
{2}{U}{B}: Proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flying
Whenever one or more other creatures die for the first time each turn, journey. (To journey, exile the top card of your library face up. Whenever a creature you control deals combat damage to an opponent, put a journeyed card you own into your hand.)

At the beginning of your end step, create a 1/1 colorless Human creature. Put a sacrifice counter on it.
Creature tokens you control with sacrifice counters on them can't attack or block and have “Sacrifice this creature: Add {C}.”

Deathtouch
When The Terror of Shady Cove enters, target opponent sacrifices an artifact. If they can't, create a 3/3 green Slug creature token with deathtouch. Then repeat this process for an enchantment and a nonbasic land.

Permanent cards in your graveyard have The Undercity Amalgam's Adventure.
Once during each of your turns, you may cast an Adventure spell from your graveyard.

Whenever The Winged Steed attacks, create a 4/4 red Dragon creature token with flying that's tapped and attacking. Exile that token at end of combat.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Prowess
Whenever you cast a noncreature spell, audition for blue or for red. (Create a 1/1 Construct Actor creature token, a Wizard Role giving 2/2 and prowess, a Warlock Role giving 2/1 and flying, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)

{T}: Draw a card. Activate only if Theoretical Scholar is embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Whenever Thicketkeeper perseveres, add {G}{G}. Until end of turn, you don't lose this mana as steps and phases end. (A creature perseveres when it survives damage.)

Flying
When Thief of Mortals deals combat damage to a player, as long as you control Thief of Mortals, gain control of target nonland permanent that player controls, and that permanent doesn't untap during its controller's untap step. Tap it.
At the beginning of each end step, if you control five or more permanents you don't own, you win the game.

{1}{B}: Target Knight or Soldier you control gains deathtouch until end of turn.

Trample
Stampede — Whenever Thoctar Yearling and a creature with greater power attack, put a +1/+1 counter on Thoctar Yearling.

Other untapped creatures have hexproof.
Whenever a creature attacks you, put a +1/+1 counter on a creature you control.

Flash
When Thraben Redeemer enters, choose up to one target permanent card in your graveyard that was put there from the battlefield this turn. Return it to your hand.

When Threshing Sundew enters, merge up to one target creature card in your graveyard under it. Threshing Sundew has that card's abilities.
When Threshing Sundew dies, return all other cards merged with it to their owner's hand.

Whenever Thrinax Sporemother or another nontoken creature you control dies, create a 1/1 green Saproling creature token.
Whenever a creature card is exiled from your graveyard, create a 1/1 green Saproling creature token.

{T}: Add one mana of any type that a land you control could produce.
Augmented — At the beginning of your end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, untap Thriving Budling and put three +1/+1 counters on it.

Trample
Once each turn, if one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on that creature instead.

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.)
Thuggish Detective can't be blocked by more than one creature.
When Thuggish Detective becomes renowned, you may destroy target noncreature permanent.

Whenever Thunderwolf attacks, exile the top card of your library. You may play that card this turn.

Creature tokens you control get +1/+1.
Whenever Thyra, Winter's Warden enters or attacks, you may pay {1}{G/W}. If you do, create Bruga, a legendary 2/2 green and white Wolf creature token.