msem-instigator

Creatures have “Whenever this creature attacks or blocks, it fights another target creature.”

Flash
When Collapsed Mine enters, exile another target nonland permanent until Collapsed Mine leaves the battlefield.

Whenever a land enters, Collapsing Realities deals 2 damage to each player.

(Add a quest counter as this enters. Sacrifice after 6.)
Whenever you cast a permanent spell, add a quest counter.
1, 2, 3, 4, 5 — Choose a color that hasn't been chosen. Search your library for a permanent card that's exactly that color, reveal it, and put it into your hand. Then shuffle.
6 — Exile Collect the World Stones. For the rest of the game, you may spend mana as though it were mana of any color.
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Enchant creature
You may cast this spell from your graveyard if it targets a legendary creature you control.
Enchanted creature gets +2/+2 and has vigilance.

At the beginning of your upkeep, exile the top card of your library. If that card has mana value 2 or less, you may play it from exile this turn.
[+1]: Create a 1/1 colorless Servo artifact creature token. If you exiled an artifact or creature card this turn, create two instead.
[0]: Create a Treasure token. If you exiled a card that had a mana ability this turn, create two instead.
[–1]: Comet deals 2 damage to any target. If you exiled an instant or sorcery card this turn, Comet deals 2 damage to any target.

Whenever a -1/-1 counter is put on a creature you control, you gain 1 life.
{1}{B}, Pay 1 life: Untap target Cleric. You may remove a -1/-1 counter from that creature.

Enchant creature
Enchanted creature must be blocked if able.

Lifelink
Partner with Imperator Valtasius (When this creature enters, target player may put Imperator Valtasius into their hand from their library, then shuffle.)
At the beginning of your upkeep, return target Soldier card from your graveyard to your hand.

Enchant creature
Enchanted creature gets +2/+2.
When enchanted creature dies, amass Soldiers 2. (Put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

When Compose from Dreams enters, you may cast any number of cards named Fatigue from your hand and graveyard without paying their mana costs.
Whenever you cast a spell, each opponent loses 1 life. Then you may draw a card if that spell wasn't cast from your hand. Then add {U}{B}{R} if you don't own that spell.

When Compulsory Studies enters, exile target creature until Compulsory Studies leaves the battlefield. Each player draws a card.

At the beginning of combat on your turn, you may exile a creature card from your graveyard. Then if a card exiled with Concoquo has flying, creatures you control gain flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Whenever you cast an enchantment spell, create a 1/1 white and black Bird creature token with flying and vigilance.
Whenever three or more creatures you control deal combat damage to a player, that player sacrifices a creature. If they can't, they discard a card.

Legacy (You may play this side of this card only from your graveyard. Exile it if it would leave the battlefield or not resolve.)
Whenever a Warrior you control becomes the target of a spell or ability an opponent controls, that player loses 1 life and discards a card, then you draw a card and gain 1 life.

Enchant creature
Enchanted creature is a blue Shaman with base power and toughness 0/2, has “{2}, {T}: Scry 1,” and loses all other abilities.

When Confine to the Oasis enters, exile target nonland permanent an opponent controls until Confine to the Oasis leaves the battlefield.
Whenever an opponent casts a spell, put a searching counter on Confine to the Oasis for each of that card's colors. Then if there are ten or more searching counters on Confine to the Oasis, sacrifice it and you gain 3 life.

(Add a quest counter as this enters. Sacrifice after 3.)
1, 2 — Whenever you attack with one or more creatures with power 4 or greater, add a quest counter.
3 — Until end of turn, target creature you control gains trample and “Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.”
Put two +1/+1 counters on target creature you control. It fights up to one target creature you don't control.

Create a 1/1 white Soldier creature token with vigilance.
At the beginning of combat on your turn, you may pay {2}{W}. If you do, creatures you control get +1/+1 until end of turn.

Whenever an opponent draws a card, you may draw a card.

Vanishing 1 (This permanent enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When the last time counter is removed from Conspiracy of Ravens, target player reveals their hand. You choose a nonland card from it. That player discards that card.

At the beginning of your end step, return target creature card with mana value X or less from your graveyard to the battlefield with a finality counter on it, where X is the greatest number of creatures you control that share a creature type.

Enchant creature or planeswalker
As Consumed by Fashion enters, put two loyalty counters on enchanted permanent.
You control enchanted permanent. It's an Okus planeswalker with “+1: Scry 1” and “-3: Draw a card” and loses all other card types and abilities.

Whenever Consuming Doom or another enchantment you control enters, you may have target creature get -1/-1 until end of turn.
Whenever a source an opponent controls destroys an enchantment you control, that player sacrifices a creature.

When Consumption Catalyst enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever you draw a card, each opponent loses 1 life and you gain 1 life.