msem-instigator

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

({T}: Add {G} or {W}.)
Timeless Shrine enters the battlefield tapped.
{1}, {T}: Add {G}{G} or {W}{W}.

Double strike (This creature deals both first-strike and regular combat damage.)
If three or more creatures are attacking you, you may cast Timely Commander as though it had flash.

Target permanent gains indestructible and hexproof until end of turn. Remove all -1/-1 counters from it.

Destroy target non-Xirix permanent. If that permanent had mana value 6 or greater, take an extra turn after this one.

If you have less life than an opponent, you gain 6 life. If you control fewer creatures than an opponent, create three 1/1 white Soldier creature tokens.

Tap target creature. If you control a Monk, draw a card. (Then exile this card. You may cast the creature later from exile.)

Flying, lifelink
When Timestream Sentinel enters the battlefield, put two +1/+1 counters on each other creature named Timestream Sentinel you control.

{T}: Add {C}.
{4}, {T}, Sacrifice Timeworn Crags: Destroy target nonbasic land. This ability costs {1} less to activate for each nonbasic land you don't control.

Whenever a creature enters the battlefield under your control, Timid Thunderhorn gets +X/+X until end of turn, where X is that creature's power.

First strike
If one or more creature tokens would be created under your control, for each of those tokens, you may create three 2/2 green Cat Warrior creature tokens instead.

First mate — Each nonland card in your starting deck is an artifact, a Pirate, or has “artifact,” “Treasure,” or “Pirate” in its printed rules text. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Whenever Tinbeard of the Brine attacks, each opponent loses X life and you gain X life, where X is the number of artifacts you control plus the number of Pirates you control.

When Tinker Tantrum enters the battlefield and at the beginning of your upkeep, you may sacrifice an artifact. If you do, reveal cards from the top of your library until you reveal an artifact card with mana value X or less, where X is 1 plus the sacrificed artifact's mana value. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

{3}: Put a +1/+1 counter on Tinkerer's Assistant.

Rapport — Whenever Tinkering Swarm and at least one other creature you control become tapped, create a token that's a copy of Tinkering Swarm.

Flying

You may pay {1}{G} and tap an untapped Soldier you control rather than pay this spell's mana cost.
Put two +1/+1 counters on target creature. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

When Tinyvale Trappings enters the battlefield, you may attach it to target creature you control with mana value 2 or less.
Equipped creature gets +3/+1.
Equip {3}

Tinyvale Treetops enters the battlefield tapped unless you played it from exile.
{T}: Add {G} or {W}.

This spell has flash as long as you control a Soldier.
When Tinyvale Watchkeep enters the battlefield, untap target creature.

Flash
Enchant creature
Enchanted creature gets +1/+1 and has first strike.

Counter target spell unless its controller pays {2}.

This spell costs {2} less to cast if you've cast another spell this turn.
Enchant creature
When Tire Out enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Advance {3}{B}{B} (Cast this for {3}{B}{B} to advance it as it enters. {3}{B}{B}: Advance this as a sorcery.)
Whenever Tireless Archivist advances, search your library for a card, put it into your hand, then shuffle.

Search your library for an artifact card with mana value X, where X is 1 plus the greatest mana value among artifacts you control, reveal it, put it into your hand, then shuffle.
You may cast Tireless Endeavor from your graveyard by sacrificing an artifact in addition to paying its other costs.