msem-instigator

Destroy target creature with power less than or equal to the number of creature cards in your graveyard.

At the beginning of your end step, you may mill a card.
{3}{B}, Exile two cards from your graveyard: Target player loses 2 life.

When Trainer of the Abyss dies, create a 1/1 black Demon Hound creature token with deathtouch.

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.

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Tranquil Cove enters the battlefield tapped.
When Tranquil Cove enters the battlefield, you gain 1 life.
{T}: Add {W} or {U}.

Choose one —
• Each player skips their next combat step.
• Each opponent can't cast instant or sorcery spells this turn.

Tranquil Shrine enters the battlefield tapped.
When Tranquil Shrine enters the battlefield, if you don't control a legendary creature, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

({T}: Add {W} or {U}.)
Tranquil Stream enters the battlefield tapped.

{T}: Add {C}.
{7}: Transplanted Citadel becomes a 6/6 Golem artifact creature until end of turn. It's still a land. This ability costs {1} less to activate for each artifact you control.

When Trapped in the Tower enters the battlefield, exile target creature an opponent controls until Trapped in the Tower leaves the battlefield. (That creature returns under its owner's control.)
When you lose life, sacrifice Trapped in the Tower.

{1}, Sacrifice Traveler's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

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.)
As long as Traveling Marshal is renowned, it has first strike.

Choose one —
• Return target creature to its owner's hand unless that player pays {1}.
• Counter target noncreature spell unless its controller pays {1}.

Treacherous Den enters the battlefield tapped.
{T}: Add {B} or {R}.
{2}{B}{R}, {T}, Sacrifice Treacherous Den: Draw a card.

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 the battlefield, if an opponent passed the trial, that player gains control of Treacherous Devil.

Bleed {1}{B} (You may cast this spell for its bleed cost if an opponent lost life this turn.)
Deathtouch
Treacherous Informant enters the battlefield with two +1/+1 counters on it if you paid its bleed cost.
You may cast spells for their bleed costs if you lost life this turn.

Treacherous Oasis enters the battlefield tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Treacherous Oasis becomes a Crocodile creature in addition to its other types. It can't be blocked this turn.
Scavenge {1}{U}{B}

{T}: Add {C}.
{3}, {T}, Sacrifice Treasure Beach: Create three Treasure tokens. (They have “{T}, Sacrifice this artifact: Add one mana of any color.”)

As Tree of Timelines enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {B}, {G}, or {U}.

{2}{B}, Sacrifice a creature: Draw a card.

Whenever a creature you control deals combat damage to a player, if it has no +1/+1 counters on it, put a +1/+1 counter on it. You gain 1 life.

As an additional cost to cast this spell, discard a land card.
Exile the top two cards of your library. Until end of turn, you may play those cards.

Deathtouch

{T}, Pay 1 life: Add {G}.
{T}, Pay 1 life, Sacrifice Tropical Grove: Search your library for a Forest card, put it onto the battlefield tapped, then shuffle.