msem-instigator

Put target attacking or blocking creature on the bottom of its owner's library.

Whenever you cast a noncreature spell, Rageborn Pyromancer gets +1/+1 until end of turn.
{1}{R}: Rageborn Pyromancer gets +1/+0 and gains flying until end of turn.

Create a 2/2 blue Jellyfish enchantment creature token with flying.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

As Sunflower Fields enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}, {G}, or {W}.

When Evolving Elemental enters, scry 3, then reveal the top card of your library. Put a number of +1/+1 counters on Evolving Elemental equal to that card's mana value.

When Gift of the Seraph enters, exile target nonland permanent an opponent controls until Gift of the Seraph leaves the battlefield. When you do, create a Weapon token and attach it to up to one target creature you control. (A Weapon token is an Equipment artifact with “Equipped creature gets +1/+1” and equip {2}.)

Return target creature you own to your hand.
Scry 1.

Haste
Herald of Unity's power is equal to the number of creatures you control.

Flash
Enchant creature
Enchanted creature gets -2/-2 and can't block creatures you control.

Enchant creature
Enchanted creature gets +3/-3.

Flying, ward {2}
Whenever Realm Crossers deals combat damage to a player, create a blue enchantment token named Tambo with “At the beginning of your upkeep, draw a card if you control a Scout.”

When Infamous Bilgecaptain enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.)
Other Pirates you control get +1/+1.
At the beginning of your end step, you may put a Pirate card with mana value less than or equal to the number of artifacts you control from your hand onto the battlefield.

Create two 1/1 white Soldier creature tokens. You gain 4 life.

If another creature you control would die, exile it instead.
When John Furo, the Unfortunate dies, until your next end step, you may play cards exiled with John Furo.

When Blacksite Moderator enters, you may pay 2 life or sacrifice a permanent. If you do, draw a card.

Prevent all damage that would be dealt to you this turn. You gain 1 life for each creature you control.

Instant and sorcery spells you cast cost {1} less to cast.

When Specialist Saboteur enters, choose one —
• Put a +1/+1 counter on Specialist
Saboteur.
• Destroy target enchantment.

When Eaveshoppers enters, each opponent discards a card.
Inspired — Whenever Eaveshoppers becomes untapped, exile up to one target card from a graveyard. If a land card is exiled this way, put a +1/+1 counter on Eaveshoppers.

Target creature gets -1/-1 until end of turn. If that creature is tapped, it gets -3/-3 until end of turn instead.

Destroy target creature. You may put a -1/-1 counter on target creature.

Calciform Wastes enters tapped. When it does, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this, then you may put that card into your graveyard.)
{T}: Add {W}.
{2}{W}{W}: Calciform Wastes becomes a Turtle creature. (This effect lasts indefinitely.)

Put two +1/+1 counters on up to one target creature.
Coalesce {6}{G}{G} (You may cast this from your graveyard for {6}{G}{G}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
When Kantra of Avarice enters, target player draws two cards and loses 2 life.

Menace
Sacrifice a creature: Devouring Flame gets +2/+0 until end of turn.