msem-instigator

Whenever you cast an instant or sorcery spell, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

At the beginning of combat on your turn, whenever target creature deals combat damage to a player this turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Queue Bouncer enters, return target creature to its owner's hand. If you control another Actor, instead put that creature on top of its owner's library.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Quick Brown Fox can't be blocked by Hounds.

Equipped creature gets +2/+0.
Equipped creature has first strike as long as it's attacking.
Equip {2}

Whenever Quick-Witted Slayer deals combat damage to a player, you draw a card and you lose 1 life.

Target creature becomes the color or colors of your choice until end of turn.
Draw a card.

The next sorcery spell you cast this turn can be cast as though it had flash.
Draw a card.

Destroy target creature or planeswalker. Create a tapped colorless land token named Fading Rift with “{T}, Sacrifice this land: Add one mana of any color.”

Reverberate {2} (When you cast this spell, copy it if you paid its reverberate cost.)
Draw a card.

Counter target spell. If a noncreature spell is countered this way, scry 2.

{T}: Quill Sniper deals 1 damage to any target if it's an opponent or if you control a storied permanent. (Enchantments and legendary permanents are storied.)

When Quillback dies, you may shuffle him into his owner's library. If you do, return up to one target Shaman creature card and up to one target non-Shaman creature card from your graveyard to your hand.

Haste
Whenever Quinn or another creature you control enters, tap all creatures your opponents control.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {G} or {U}.

Attacking creatures you control have first strike.
Whenever Qulai, Orchard Guardian attacks or becomes the target of a spell or ability an opponent controls, conjure a card named Fox of the Orange Orchard into your hand. (It's a {1}{W} 3/1 Fox Spirit creature.)

When Qulai enters, look at the top six cards of your library. You may reveal a Fox card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
Sacrifice Qulai: Foxes you control gain hexproof and indestructible until end of turn.

When R-12 Lone Digger enters, it deals 3 damage to target player or planeswalker.

Deathtouch
Whenever a creature dealt damage by Rabid Rodent this turn dies, put a +1/+1 counter on Rabid Rodent.
{2}, Remove a +1/+1 counter from Rabid Rodent: Regenerate Rabid Rodent.

Creatures you control get +2/+0.
Whenever a creature you control is dealt damage, it deals that much damage to you.

When Rabudan Chiseler enters, you may search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Enchant opponent
Whenever enchanted player is attacked, choose an attacking creature. Create a tapped and attacking token that's a copy of it. Exile the token at the beginning of the next end step.

Enchant nonland permanent
Enchanted permanent can't attack and its activated abilities can't be activated.

Enchant creature
Enchanted creature gets +1/+2 and has flying.

Flying
Whenever a creature you don't control deals damage, its controller sacrifices it unless that player pays {2}.