msem-instigator

First strike, haste
When Mounted Marksman enters, it deals 2 damage to target creature you don't control.

Hexproof
Whenever an opponent casts a spell or draws a card, draw a card.

Until the end of your next turn, you may play a red card you own from outside the game. Add {R}{R}.

Haste
Whenever Shala's Phantasm attacks, you may sacrifice a creature. If you do, Shala's Phantasm deals 3 damage to any target.

Destroy target colorless nonbasic permanent. Harsh Erosion deals 2 damage to that permanent's controller.

Flying
When Foul Drifter enters, target creature gets -1/-1 until end of turn.

{X}, {T}, Sacrifice Macabre Ruins: Target creature gets -X/-X until end of turn.

Gain control of target artifact or creature until end of turn, then untap it. It gains haste until end of turn. You may spend mana as though it were mana of any type to pay the costs of its abilities this turn.

You may have Shaper of the Formless enter as a copy of any creature on the battlefield, except it has “{2}{U}: Target face-down creature becomes a copy of this creature until end of turn. Turn that creature face up. At the beginning of the next cleanup step, turn it face down.”

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
Create a 1/1 white Cleric creature token. If the trial was failed, create three of those tokens instead.

When Rei's Cultivator enters, create a green Aura enchantment token named Sowing Spring attached to target land. The token has enchant land, “Enchanted land's name is Flowering Expanse” and “Whenever enchanted land is tapped for mana, add one mana of any color.”

You may have Insipid Metamorph enter as a copy of any other creature on the battlefield, except it's 1/1.

Menace (This creature can't be blocked except by two or more creatures.)

Exile any number of target cards in exile. (They become new objects that have just been exiled.)
Draw a card.

Target creature you control gets +X/+X until end of turn, where X is the number of +1/+1 counters among creatures you control.

You may play an additional land on each of your turns.
{4}{U}{U}: Transform Misthollow Rites. Activate only as a sorcery.

Flash
Flying
When Gale Conjurant enters, return target spell to its owner's hand if its mana value is less than or equal to the number of creatures in Gale Conjurant's pack. (Two or more creatures you control with equal power are in a pack.)

{T}: You may put a land card from your hand onto the battlefield.
{1}, {T}: Aetherize target land you control. (To aetherize, create a token that's a copy of it, then exile that token.)

Target player mills four cards.
Inscribed creature has flying.
Inscribe {2}{U} ({2}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying
Whenever Notorious Windraider attacks, other attacking Pirates and Rogues you control gain flying until end of turn.

Flying
Whenever you aetherize, you may have Telarine Skychaser become an artifact creature until end of turn.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Trample
While you're searching your library, if Shambling Manglers dealt combat damage to an opponent this turn, you may play lands from your library.

Flash
Flying
Whenever H13 Wasp enters or you cast an another spell with flash or an instant, exile up to one target nonland permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Attain {4}{U} ({4}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Choose any number —
• Each player loses X life.
• Each player discards X cards.
• Each player sacrifices X creatures.
• Each player sacrifices X lands.