msem-instigator

Each opponent sacrifices an artifact.
Scry 1.
Coalesce {6}{R} (You may cast this from your graveyard for {6}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Haste
When Wretched Merfolk enters, target creature can't block this turn.

When Wu, the Shackled enters, you may have an opponent gain control of it. If you do, draw two cards.
At the beginning of your upkeep, if you don't own Wu, it fights another target creature you control and its owner draws a card.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{4}{G}: Target creature gets +2/+2 until end of turn.

When Yamisaran Bladedancer enters, you may attach an Equipment you control to target creature you control.

Reach
{T}: Yangzhi Cloudpiercer deals 1 damage to target player or planeswalker.

Menace
Yaran's Enforcer gets +1/+1 as long as you foretold a card this turn.
Yaran's Enforcer gets +1/+1 as long as you cast a foretold spell this turn.

{2}, Exile a land card from your graveyard: Create a token that's a copy of that land.

Flying
When Yielder of Ambition enters, target creature gets +2/+2 until end of turn.
Fleeting {W} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Whenever you cast a spell, harmonize twice. (To harmonize, trigger up to one harmony of a permanent you control.)
Harmony — Yita, Almgrove Prodigy gains your choice of flying, first strike, vigilance, lifelink, hexproof, or haste until end of turn.

When Young Chasqui enters, if you cast it, reveal the top five cards of your library. Put any number of creatures named Young Chasqui from among them into your hand. Put the rest of the revealed cards on the bottom of your library in a random order.
A deck can have any number of cards named Young Chasqui.

Young Dragonheart gets +1/+0 and has first strike as long as you control a legendary creature.

Wanderlust — Whenever a land you control enters, if you control four or more differently named lands, create a 1/1 green Saproling creature token.

Whenever you cast an instant or sorcery spell, tap target creature an opponent controls.

Whenever a nontoken creature you control dies, create a 1/1 black Skeleton creature token.

Whenever you cast a cryptic spell, create a 1/1 white Human creature token with lifelink. (Artifacts, enchantments, and modal spells are cryptic.)

Other Rebel creatures you control get +1/+0.
When Youthful Renegade enters, create a 1/1 white Rebel creature token.

Whenever Yri, the Daring Blade and exactly one other creature attack, Yri and that creature can't be blocked by creatures with mana value 3 or less this turn.

Vigilance
Art of war — At the beginning of your end step, if Yuso, Light of Jidai dealt damage to an opponent this turn, you may search your library for a creature card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Whenever Zana, the Dreamer attacks, you may pay {3}{R}{R}. If you do, for each attacking nontoken creature you control, create a tapped and attacking token that's a copy of it, except the tokens aren't legendary. Exile those tokens at the beginning of the end step.

This spell costs {1} less to cast for each creature that died this turn.
At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control.
{1}, Sacrifice another creature: Zarad, the Final Adversary gains indestructible until end of turn.

{1}{R}, {T}, Sacrifice a land: Create a colorless Desert land token with “{T}: Add {C}.”
{1}{R}, {T}, Sacrifice a Desert: Destroy up to two target lands.

Other creatures you control get +3/+0.
When Zare enters, create a 2/1 white Bird creature token with flying and a 3/3 green Horse creature token.
Whenever another creature you control attacks or blocks, sacrifice it at end of combat.

Zareen's Pariah is all colors.
Flying
During each of your turns, you may cast a spell of each color from your graveyard.

Whenever two or more creatures an opponent controls block, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Enchanted creatures you control have menace.