msem-instigator

Return all nonland permanents to their owners' hands. Each player shuffles their graveyard into their library. Exile Turn Back Time.

Each player chooses three permanents they control, then returns the others to their owners' hands. Each player loses all unspent mana.
Exile Turn the Record Over.

Flash
Enchant artifact or creature
Enchanted permanent is an artifact with “{T}: Draw a card then discard a card” and loses all other card types and abilities.

Flying, lifelink
Sacrifice a creature: Until end of turn, Turned Watcher gets +1/+0 and gains “Whenever Turned Watcher deals combat damage to a player, draw a card.”

Trample
Whenever Tusked Consumer or another creature with power 4 or greater enters the battlefield under your control, purge. (Exile two cards that share a type from graveyards. If you do, draw a card.)
Whenever one or more cards are put into exile from anywhere, you gain 1 life.

Respawn (When this creature dies, if it attacked this turn, return it to its owner's hand.)
When Tutorial Boss enters the battlefield, create a 1/1 blue Pirate creature token.

If you would gain life, you gain twice that much life instead.
If you would draw a card, draw two cards instead.
If you tap a permanent for mana, it produces twice as much of that mana instead.

When Twice-Lived Dead dies, create a 2/2 black Zombie creature token.

Exchange control of all creatures you and target player control until end of turn. Untap those creatures. They gain haste until end of turn.

{1}{U}: Twilight Privateer voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Twilight Privateer phases in, up to one other target creature voyages.

Whenever Twilight Walker perseveres, target creature doesn't untap during its controller's next untap step. (A creature perseveres when it survives damage.)

Each creature you control with a +1/+1 counter on it has double strike.
If one or more +1/+1 counters would be put on a creature you control, put that many plus one +1/+1 counters on that creature instead.

Choose one—
• Scry 3. Draw a card.
• Fateseal 3. That player draws a card. (To fateseal 3, look at the top three cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Other creatures you control have base power and toughness equal to this creature's base power and toughness.

Flying, haste
Whenever another creature dies, Twinfire Dragon gets +1/+0 until end of turn.

When Twinforged Golem enters the battlefield, create a 3/3 colorless Golem artifact creature token.

Attacking creatures have winnow. (Damage dealt to a creature with winnow also causes its controller to lose that much life.)

Hexproof
Whenever Twinning Psionic harnesses an instant or sorcery spell, you may copy that spell. If you do, you may choose new targets for the copy.

Harmony — Creatures you control gain double strike until end of turn.
When Twirling Duet enters the battlefield, harmonize. (Trigger up to one harmony of one permanent you control.)

Flying, menace, haste
Twisted Archangel has indestructible as long as an opponent has four or more cards in hand.

Menace
Chosen one ({W}{U}{B}{R}{G}: Transform this permanent.)

Each player sacrifices two creatures, then gains 2 life and draws a card for each creature they sacrificed this way.

Creature tokens you control get +1/+1 and have distorted. (They can be blocked by tapped creatures but not untapped creatures.)

Create two 1/1 blue Bird creature tokens with flying and “When this creature dies, draw a card.”