msem-instigator

At the beginning of your first main phase, choose one —
• Artifact spells cost {1} less to cast until your next turn.
• Nonartifact spells cost {1} more to cast until your next turn.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Heroic — Whenever you cast a spell that targets Aegis Hero, put a +1/+1 counter on Aegis Hero.

Whenever a nonbasic nontoken land enters under an opponent's control, create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

Flying
Whenever Buzzing Flitter attacks, you may pay {G}. If you do, untap target permanent.

Colossal 2—{5}{G}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {5}{G}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
Flying
Each creature you control with a counter on it has vigilance and “{T}: Add one mana of any color.”

Flash
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{W}{B}: Kirishima's Escort gets +1/+1 and gains first strike until end of turn.

As long as Shambling Morass is on the battlefield or in your graveyard, it's a land in addition to its other types.
When Shambling Morass dies, you may pay {1}. If you do, you draw a card and you lose 1 life.

When Return to the Home Plane enters, draw a card, then choose a card name.
Spells you cast with the chosen name cost {G/U}{G/U} less to cast and may be cast as though they had flash. This effect reduces only the amount of colored mana you pay.

Creatures you control get +2/+0 until end of turn.
Whenever an opponent fails a trial, if Combatant Conflagration is in your graveyard, target creature you control gets +2/+0 until end of turn.

Defender
Prismatic — Whenever you cast a multicolored spell, Squall Serpent gets +1/+1 until end of turn and can attack this turn as though it didn't have defender.

Vigilance, menace, trample, haste
Whenever you cast a spell, you may have Thunderous Avarice consume. If you do, put a +1/+1 counter on it. (To consume, sacrifice another creature or exile a creature card from your graveyard.)
Whenever an opponent casts a spell, they may have Thunderous Avarice consume. If they don't, put a +1/+1 counter on it.

(Choose only one work as a sorcery to add its ability.)
When Those Lost to the Waves enters, search your library for an artifact card with mana value 3 or less, reveal it, put it into your hand, then shuffle.
{1}{W}: Fight the Current
Equipped creatures you control get +1/+1.
{3}{U}: Soul of the Sea
At the beginning of combat on your turn, you may have target noncreature artifact become a 3/3 artifact creature until end of turn.

Crafter's Mistake deals 1 damage to target player or planeswalker. That player or that planeswalker's controller sacrifices an artifact.

Target creature gets +2/+1 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Relic Hoarder gets +1/+0 for each artifact and/or enchantment you control.
Relic Hoarder has first strike as long as you control three or more artifacts and/or enchantments.

{3}, {T}, Reveal a card at random from your hand: Draw a card.

Whenever you cast your second spell each turn, create a 1/1 blue Jellyfish Spirit creature token with flying.

Return target permanent to its owner's hand. If this spell wasn't cast from your hand, put that permanent on top of its owner's library instead.
Coalesce {9}{U} (You may cast this from your graveyard for {9}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Create three 1/1 black Insect creature tokens with flying, then judge each of them. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

Whenever a creature you control enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
{2}, Sacrifice an Idol: Creatures you control get +1/+1 until end of turn.

Exile target creature with mana value 2 or less.

Deathtouch
{3}{G}: Deathcoil Cobra gains indestructible until end of turn.

{2}{U}{B}: Return Depth Charger to its owner's hand. If you do, return target creature to its owner's hand. That player discards a card.

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.

Enchant land
Whenever enchanted land is tapped for mana, its controller adds an additional {G}.
{1}{G}, Sacrifice Allure of the Woods: Draw a card.