msem-instigator

Flash
When Agent of Deception enters, counter target creature or planeswalker spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

When Dawn Silhouette enters, you may exile target creature not named Dawn Silhouette you control, then return that card to the battlefield under your control.
Mirage {1}{W} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{G}: Mill three cards. Target creature gets +X/+X and gains trample until end of turn, where X is the number of land cards in your graveyard.

Artifact vision (Whenever this or another artifact you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Mechanomind Researcher envisions an artifact card, put a +1/+1 counter on it.

Flying, haste
Miyoga Firebird attacks each combat if able.
Whenever you cast your third instant or sorcery spell this turn, you may return Miyoga Firebird from your graveyard to the battlefield.

{R}, Sacrifice Nacatl Skirmisher: Destroy target artifact.
Stampede — Whenever Nacatl Skirmisher and a creature with greater power attack, creatures you control get +1/+0 until end of turn.

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)
Sacrifice another artifact: Put a +1/+1 counter on Plasma Enforcer.
When Plasma Enforcer dies, create a 1/1 colorless Servo artifact creature token for each +1/+1 counter on Plasma Enforcer.

Destroy target land. Its controller creates a colorless Desert land token with “{T}: Add {C}.”

Whenever a creature you control dies, Twilight Blade deals 1 damage to each opponent and you gain 1 life.

Flying
When Witch of Spring's Promise enters, shuffle any number of cards from your hand into your library, then draw that many cards plus one.