msem-instigator

{1}{G}, Discard Hibiscus Snapdragon: Create a Treasure token.
Scavenge {4}{G} ({4}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Counter target spell. If a permanent spell is countered this way, create a token that's a copy of that card except it's a colorless creature, it's 2/2, and it's a Plant in addition to its other types.

Flying
Morph {3}{B}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Ishim of Genesis is turned face up, put a +1/+1 counter on it, then return target instant or sorcery card from your graveyard to your hand.

When Fearless Recruit dies, create a 1/1 white Rebel creature token.

Whenever an opponent casts a spell, that player mills X cards, where X is that spell's mana value.

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{5}: Each opponent sacrifices a nonland permanent.

Double your life total. (Then exile this card. You may cast the creature later from exile.)

When Gilded Merrow enters, if an opponent controls more lands than you, create a Treasure token. (It's an artifact with “{T}, Sacrifice this permanent: Add one mana of any color.”)

Flying, lifelink
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Recreator of Myths attacks, you may cast target instant or sorcery spell from your graveyard. If you do, exile that card instead of putting it into your graveyard as it resolves.

Target creature gains haste until end of turn. Make an Entrance deals 2 damage to up to one target creature.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.

Flying
Whenever an opponent discards one or more cards, fateseal 1. (To fateseal 1, look at the top card of an opponent's library, then you may put it on the bottom of that player's library.)

Until end of turn, target blocked creature you control gains trample and “Whenever this creature deals combat damage to a player, draw that many cards.”

{T}: Add one mana of any color a basic land you control could produce.

{U}, Put a travel counter on Endless Discoveries: Draw a card. This ability costs {1} more to activate for each travel counter on Endless Discoveries.
{3}{U}{U}, Sacrifice Endless Discoveries: Return target instant or sorcery card with mana value less than or equal to the number of travel counters on Endless Discoveries from your graveyard to your hand.

Doomsday Horde enters tapped unless it was foreshadowed.
When Doomsday Horde dies, search your library for a card, put it into your hand, then shuffle.
Foreshadow {3}{B}{B}{B} (You may cast this spell for its foreshadow cost. If you do, also trigger its “dies” abilities when it enters.)

Choose one —
• Paint with Starflame deals 3 damage to target player or planeswalker. Scry 1.
• Create a 2/2 red Elemental Shaman creature token with haste and “Whenever this creature attacks, scry 1.”

When Voltaic Conduit enters, it deals 5 damage to target creature or planeswalker you don't control.
Whenever you attack, you may discard a card. If you do, draw a card.

Spend only black mana on X.
Up to two target creatures each get -X/-X until end of turn. You gain X life.

{T}: Add three mana of any one color.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{1}{B}, Sacrifice a creature: Put a +1/+1 counter on Twisted Cultist.

When Sihari's Groundblazer enters, create a red Aura enchantment token named Searing Crags attached to target land. The token has enchant land, “Enchanted land's name is Charred Causeway” and “Enchanted land has {T}: This land deals 1 damage to each opponent.”

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
Discard a card, then draw a card. If the trial was failed, you may instead discard two cards. If you do, draw two cards.

Starting with you, each player either passes or reveals the top card of their library. Each player that revealed a card this way pays life equal to its mana value. If a player can't, that player passes. Then each player who hasn't passed yet puts that card into their hand. Repeat this process until each player has passed.