msem-instigator

Haste
At the beginning of combat on your turn, create two nonlegendary token copies of Thrice-Clawed Troika. Then for each creature token created this way, create token copies of each permanent attached to Thrice-Clawed Troika and attach them to that creature token. Exile all tokens created this way at end of combat.

Each creature you control enters the battlefield with an additional +1/+1 counter on it.
Each planeswalker you control enters the battlefield with an additional loyalty counter on it.

Whenever a permanent an opponent controls becomes the target of a spell you control, put a progress counter on Throne of the West.
[PROGRESS 2+] {T}: Gain control of target permanent until end of turn. Untap it. It gains haste until end of turn.
[PROGRESS 5+] You can't lose control of permanents.

When Through the Dust enters the battlefield, it becomes an Aura with enchant creature. Reveal the top seven cards of your library, put a creature card revealed this way onto the battlefield and attach Through the Dust to it. Then put the rest on the bottom of your library in any order. When Through the Dust is no longer on the battlefield, enchanted creature's controller sacrifices it.
Mirage {1}{U}{U}{U}

Creature tokens you control get +1/+1.
Whenever Thyra, Winter's Warden enters the battlefield or attacks, you may pay {1}{G/W}. If you do, create Bruga, a legendary 2/2 green and white Wolf creature token.

Enchant creature
When Til Death enters the battlefield, exile target creature an opponent controls other than enchanted creature until Til Death leaves the battlefield.
Enchanted creature has defender.

Instant and sorcery spells you control have leitmotif. (Exile that spell as it resolves if you cast it from your hand. When you next cast a spell that shares a color with that card, you may cast it from exile without paying its mana cost.)

{16}, {T}: Time Cube gains “At the beginning of your end step, if it's not an extra turn, take three extra turns after this one” and loses this ability.

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.

Your opponents can't search libraries unless they pay {2}.
[+2]: If an opponent has more life than you, you gain 2 life.
[0]: If an opponent controls more creatures than you, you create two 1/1 white Gnome creature tokens.
[–4]: Search your library for a creature card with mana value 2, put it onto the battlefield, then shuffle.

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

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.

Nonstoried creatures lose all abilities and have base power and toughness 1/1.

Enchant creature without flying
Enchanted creature gets +10/+0 and attacks each combat if able.

When Titou Louoe, Bayou Shaman enters the battlefield, create a blue Aura Curse enchantment token named Curse of Impotence attached to target player. The token has enchant player and “Creatures enchanted player controls get -1/-0.”

When To Go Beyond enters the battlefield, draw a card, then choose a card name.
{2}{U}: Reveal a card you own from outside the game with the chosen name and put it on top of your library.

Creatures you control get +1/+1.
{3}{W}{W}, Sacrifice To a Bright Future: Put a +1/+1 counter on each creature you control.

Enchant creature
Spirited (When this enters the battlefield, you may activate one of its activated abilities without paying its cost.)
{1}: Enchanted creature can't attack or block this turn.

At the beginning of each end step, put a +1/+1 counter on equipped creature for each creature that died this turn.
Equip {1}

Enchant creature
When Tomb Robber's Grit enters the battlefield, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Enchanted creature gets +1/+1.

Tomb of the Roseblade enters the battlefield tapped.
{T}: Add {C}.
{X}, {T}, Sacrifice Tomb of the Roseblade: Search your library for an Equipment card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Reach
You may have other creatures you control enter the battlefield as a copy of any creature card in a graveyard with equal or lesser mana value.

{X}{X}{W}, {T}, Sacrifice Tome of Loss: Return each creature card with mana value X or less from your graveyard to the battlefield.