msem-instigator

Draw three cards, then discard two cards unless you discard a multicolored card.

Rhapsody {4}{U}{U} (Pay {4}{U}{U} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever you draw a card, any number of target players mill two cards.
Whenever This Is Not Our Fate deals combat damage to a player, for each player, you may cast an instant or sorcery card from that player's graveyard without paying its mana cost.

Other creatures have haste and attack each combat if able.
Nonland cards in your hand have paranoia {4}. (The owner of a card with paranoia {4} may cast it from their hand for {4} when a permanent they control leaves the battlefield.)

When Thorn Tender enters, rouse 1, then put a +1/+1 counter on each creature you control. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

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

Flash
When Thornweald Cavalier enters, target creature gets +1/+1 until end of turn. Put a reach counter on it.

Whenever a creature enters under an opponent's control, draw a card unless that player pays {1}.

Untap target creature and gain control of it until end of turn. That creature gains haste until end of turn.

Attacking creatures get +2/+0 until end of turn.
Armed — Equipped creatures you control get an additional +1/+0 until end of turn.

Reveal the cards in your library. Target opponent chooses three nonland cards with different names from it. You put the chosen cards into your hand. Then shuffle.

Whenever a creature you control phases in, it gets +2/+2 until end of turn.

Target creature gets -3/-3 until end of turn. Its controller loses 3 life. You mill three cards.

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.

Vigilance, trample
When Threshold Guardian enters, return a creature you control to its 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.

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.

Augmented — When you cast this spell, if it's your turn and you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy it twice. You may choose new targets for the copies.
Thunder Road deals 3 damage to any target. You gain 3 life.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Attacking creatures get -3/-0 until end of turn.
3 | Thundering Wrath deals 1 damage to each of those creatures.

Flash
Whenever Thundermane Fox enters or attacks, target creature you control gains double strike until end of turn.

Flash
Cycling {2} ({2}, Discard this card: Draw a card.)

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.

Whenever Tide Crasher attacks, if you control another Merfolk, tap target creature defending player controls.

Permanents you control gain indestructible until end of turn. Untap each creature you control.
Cycling {W} ({W}, Discard this card: Draw a card.)

Kicker {X}{U} (You may pay an additional {X}{U} as you cast this spell.)
When Tidetwister Mage enters, if it was kicked, return all other creatures with power X or less to their owners' hands.

Return target permanent to its owner's hand. If this spell wasn't cast from your hand, put that permanent on top of its owner's library instead.
Coalesce {9}{U} (You may cast this from your graveyard for {9}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)