msem-instigator

When Intrepid Shieldmate enters, target creature gets +1/+1 until end of turn.

Lifelink
{2}{B}: Create a 1/1 black Human Warlock creature token with lifelink.
{4}{B}{B}{B}, Pay 7 life: Transform Oswin, Skirsdag Diabolist.

Into Waiting Jaws deals 5 damage to target creature. If you sacrificed a permanent or discarded a card this turn, Into Waiting Jaws deals 3 damage to that creature's controller.

If you would catalyze, catalyze twice instead. (The next spell you cast this turn costs {1} less to cast.)
You may pay an additional {2} as you cast a spell. If you do, reveal the bottom card of your library. You may put it into your graveyard or on top of your library.

Whenever Desperate Thief deals combat damage to a player, you may pay 2 life. If you do, draw a card.

Nonartifact spells cost {1} more to cast.

Wither (This deals damage to creatures in the form of -1/-1 counters.)
When you unveil Bramble Quickling, you may have it fight target creature.

When Explorer's Torch enters, draw a card.
Equipped creature gets +1/+1.
Equip {1}

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
{1}{R}, Remove a +1/+1 counter from Lt. Daisy Saxon: She deals 2 damage to target player or planeswalker.

Target creature can't block this turn.
Draw a card.

[+1]: You may sacrifice a permanent. If you do, each opponent sacrifices a permanent that shares a type with it.
[–2]: Put target creature card in a graveyard onto the battlefield under your control.
[–8]: You control target player during their next turn. During that turn, that player may cast spells by paying life equal to their mana value rather than pay their mana cost. After that turn, that player takes an extra turn.

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Trample
Whenever Attuned Slayer deals combat damage to a player, exile that many cards from the top of your library. You may play those cards this turn.

Destroy target artifact or land.

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

Whenever Dancing Lion attacks, if it was crewed by two or more creatures in the same pack this turn, create a tapped and attacking token that's a copy of one of them. Sacrifice the token at the beginning of the next end step. (Two or more creatures you control with equal power are in a pack.)
Crew 2

When Destiny Beyond Measure enters, tap each creature you control.
Creatures you control get +8/+8 and have “This creature enters tapped.”

Ferocious — Whenever a creature with power 4 or greater you control enters, Mieng, Who Dances With Dragons becomes a 4/4 Dragon creature with flying until end of turn.

Flying
Whenever you foretell a card or cast a foretold spell, each opponent loses 3 life unless they sacrifice a creature or discard a card.

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Croakfolk Marsh-Baron enters with X +1/+1 counters on it. If its tithe was paid, it enters with twice X +1/+1 counters instead.

Target opponent discards two cards. You create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”

Exile up to two target creatures controlled by different players. Return those creatures to the battlefield under their owners' control at the beginning of the next end step.

Flying, lifelink
When Helar's Herald dies, target opponent may give themselves two poison counters. If they do, return Helar's Herald to its owner's hand. Otherwise, return Helar's Herald to the battlefield tapped under its owner's control.

Proliferate (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
Scry 2, then draw a card.