msem-instigator

Exile all creatures, then for each creature exiled this way, you may return it to the battlefield under its owner's control. For each creature you didn't return to the battlefield this way, its owner may search their library for a basic land card and put it onto the battlefield tapped. Each player that does shuffles.

Flying
If Liguno, Who Transcends All or another permanent you control would be put into a graveyard from the battlefield, exile it instead. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Flying
Whenever you cast an instant or sorcery spell, put a +1/+1 counter on Mirrorfuse Angel, then copy that spell for each +1/+1 counter on Mirrorfuse Angel. You may choose new targets for the copies.

Enchant opponent
You control enchanted player except during their extra turns.
At the beginning of enchanted player's end step, if it isn't an extra turn, they take an extra turn after this one.

Trample
Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
When Nonpareil of the Abyss enters the battlefield, create an Idol token.
Nonpareil of the Abyss has ward {8} as long as you're in a renaissance.

Flying
Whenever Novaheart Dragon enters the battlefield or attacks, you may take an extra turn after this one. If you do, you lose the game at the beginning of that turn's end step.

This spell costs {1} less to cast for each artifact and/or enchantment you control.
Trample
Exile a cryptic permanent you control or a cryptic card from your graveyard: Observer of Aeons gets +1/+1 until end of turn.

Pressure—{4}{U}{B}, Sacrifice two creatures. (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Whenever Oryxyth enters the battlefield or attacks, create an X/X black Horror creature token, where X is the number of cards in your graveyard.
{U}{B}, Sacrifice another creature: Gain control of target creature with power less than the sacrificed creature's power.

{8}: Create eight 1/1 blue Tentacle creature tokens.
{8}: Counter target spell unless its controller pays {8}.
{8}: Draw eight cards.

You may cast this spell by paying {1}{W}{U}{B}{R}{G} rather than paying its mana cost.
Defender, indestructible
Lands you control are 2/2 Spirit creatures with haste and indestructible.

For each pair of basic land types, create a tapped colorless land token of those types. (The basic land types are Plains, Island, Swamp, Mountain, and Forest.)

For each permanent your opponents control, create a token that's a copy of that permanent.

Pyrostorm deals 10 damage divided as you choose among any number of targets.

Trample
Whenever Quakestep Behemoth or another creature enters the battlefield under your control, put X +1/+1 counters on each creature you control, where X is that creature's power.

This spell costs {1} less to cast for each artifact and enchantment you control.
Reveal the top seven cards of your library. Put any number of noncreature, nonland cards from among them into your hand and the rest of the revealed cards into your graveyard.

Flying, menace
When Riftkeeper Entity enters the battlefield, discard your hand, then draw cards equal to the number of differently named lands you control.
{1}{R}, Discard Riftkeeper Entity: Create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

This spell costs {1} less to cast for each instant and/or sorcery card in your graveyard.
Once each turn, when you cast an instant or sorcery spell, you may create a 4/4 white Angel Cleric creature token with flying and vigilance.

This spell costs {2} less to cast for each creature that died this turn.
Each player exiles all creature cards from their graveyard, then sacrifices each creature they control, then puts all creature cards they own exiled this way onto the battlefield. Exile Sea of Corpses.

Concord — This spell costs {4} less to cast if there are four or more card types among permanents you control.
Vigilance, trample, lifelink, haste

[+2]: Exile any number of target artifacts and/or enchantments you control, then return them to the battlefield under your control. You may draw that many cards.
[–4]: Search your library for an enchantment card, put that card onto the battlefield, then shuffle.
[–12]: Put any number of permanent cards you own from outside the game onto the battlefield tapped.

When Shojiro, the Wavewaker enters the battlefield, submerge up to eight target creatures your opponents control. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

This spell costs {2} less to cast for each face-down creature you control.
Flying

This spell costs {1} less to cast for each poison counter your opponents have.
Poisonous 1 (Whenever this creature deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)
At the beginning of your end step, each opponent with seven or more poison counters loses the game.