msem-instigator

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.)

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.

As an additional cost to cast this spell, discard a card.
Draw two cards.

Torrent of Ankuliths deals 5 damage to target creature. Create a 1/1 red Elemental creature token.

Trample
{4}{R}{R}: Tortle Tinkerer explores. This ability costs {1} less to activate for each artifact you control. (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.)

Haste
Whenever Tortle Waymaker becomes blocked, 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.)

As an additional cost to cast this spell, you may discard a card. If you do, this spell costs {4} less to cast.
Total Process Failure deals 5 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

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

Trample

Towering Inferno deals X damage to each creature without flying. If a creature you don't control dealt damage this way would die this turn, exile it instead.

Haste
Sacrifice a land: Trail Blazer explores. You may put a basic land card from your hand onto the battlefield tapped. (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.)

Whenever a nonland permanent enters under an opponent's control this turn, gain control of that permanent until the end of your next turn. It gains haste until end of turn.

When you cast this spell, copy it for each player that has 8 or less life. (The copies have the same target.)
Traitor's Execution deals 3 damage to target player.

Puzzlebox (Begin the game with this and another card you own from outside the game in the command zone, locked. That card is face down until you unlock this.)
{2}, Discard your hand: Unlock Traitor's Gambit. If the revealed card is red, put it into your hand. Otherwise, put it on top of your library.

When Transformative Paints enters, create a 1/1 white Human creature token, then attach Transformative Paints to it.
Equipped creature gets +1/+0 and has prowess.
Equip {3}

Create two 1/1 red Elemental creature tokens.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may change the targets of up to one target spell or ability.

Up to two target creatures can't block this turn.

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
When Treacherous Devil enters, if an opponent passed the trial, that player gains control of Treacherous Devil.

Haste
When Treasure Haulers enters, you may salvage an artifact card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)

When Treasure Hoard enters, create a 2/2 blue Rogue creature token.
{2}{R}, Tap an untapped creature you control, Sacrifice Treasure Hoard: Create two Treasure tokens. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Whenever Tremor Elemental enters or you draw a card except during your draw step, Tremor Elemental deals 1 damage to each creature.

Whenever Tremor Titan enters or attacks, each player sacrifices a permanent. Then you draw a card for each opponent who sacrificed a land this way.

When Trepid Deserters enters, target creature you control gets +2/+0 until end of turn.

Goblincycling {1}{R}, Warriorcycling {1}{R} ({1}{R}, Discard this card: Search your library for a Goblin or Warrior card, reveal it, and put it into your hand. Then shuffle.)