msem-instigator

Choose a nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles. For each card exiled from their hand this way, you discard a card.

Creatures you control have “When this creature becomes tapped for the first time during each of your turns, untap it.”
{T}: Add one mana of any color.

When Traversing Bulkvine enters, search your library for three land cards with different names and reveal them. An opponent chooses one of them. Put that card into your graveyard and the rest into your hand, then shuffle.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast your first instant or sorcery spell each turn, copy that spell. You may choose new targets for the copies.

For each permanent type, return up to one target card of that type from your graveyard to your hand. (The permanent types are artifact, creature, enchantment, land, and planeswalker.)

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

Bleed {1}{B} (You may cast this spell for its bleed cost if an opponent lost life this turn.)
Deathtouch
Treacherous Informant enters 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 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}

When Treacherous Warden enters, search your library for a card, put into your graveyard, then shuffle.
Whenever a creature enters from your graveyard, each opponent loses 2 life and you gain 2 life.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you scry or search your library, add a quest counter.
Target creature you don't control gets -3/-0 until your next turn.
Reveal cards from the top of your library until you reveal a nonland card, then put the revealed cards into your hand.
Reveal the top card of your library. If its mana value is less than or equal to the number of cards in your hand, you may cast it without paying its mana cost.

Untap all other artifacts you control during each other player's untap step.
{T}: Untap another target permanent.

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

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Treecrawler Elemental, you may have it fight target creature. (Each deals damage equal to its power to the other.)

When Trenchbottom Mariners enters, you lose 3 life, mill three cards, and create a Treasure token.
Whenever Trenchbottom Mariners attacks, you may cast a permanent card from your graveyard by sacrificing another artifact in addition to paying its costs.

This spell costs {1} less to cast for each card you've drawn this turn.
Create three 1/1 white Soldier creature tokens.

Each player sacrifices a creature. (Then exile this card. You may cast the artifact later from exile.)

When Trident of Benediction enters, create two 1/1 white Merfolk creature tokens.
Equipped creature has vigilance and “Whenever this creature attacks or blocks, creatures you control get +1/+1 until end of turn.”
Equip {2}

Erratic, erratic, erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order. Repeat this process twice.)

Whenever an opponent casts their first spell each turn, that player may pay {1}. If they don't, you may create a Treasure token and you may draw a card.

Copy target spell twice. You may choose new targets for the copies. (A copy of a permanent spell enters as a token.)

Pressure {1}{G}{G} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Trample
Whenever Triplicate Monstrosity deals combat damage to a player, draw a card.

If you would put one or more counters on a creature you control or on yourself, put that many plus one of each of those kinds of counters on that creature or player instead.
{2}{G}{U}, Sacrifice Triton's Invocation: Draw cards equal to the greatest number of counters among creatures you control and yourself.

Creatures you control gain double strike until end of turn. Whenever a creature you control deals combat damage this turn, put a +1/+1 counter on it.

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 cast a noncreature spell, Triumvirate Inductee gets +1/+1 until end of turn. Then if its power is 4 or greater, you may tap or untap target permanent.

{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.