msem-instigator

Whenever a player casts an instant or sorcery spell that targets exactly one creature they don't control, you may copy that spell. If you do, you may choose new targets for the copy.

When Clairvoyant Mage enters, scry 2. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
Whenever you cast a spell that doesn't share a color with Cloudstep Capuchin, Cloudstep Capuchin gains flying and hexproof until end of turn.

Flying
When Curator of Curios enters, draw a card for each glory counter you have.

Whenever Daisite Express attacks, draw a card.
Whenever Daisite Express deals combat damage to a player, discard a card.

Flash (You may cast this spell any time you could cast an instant.)
When Dazzling Voidmage enters, you may return target attacking creature to its owner's hand.

Flying
When Dealer of Pointed Fortunes enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Detached Specters.

When Dewdrop Oracle enters, reveal the top four cards of your library. You may put a noncreature card from among them into your hand. Put the rest on the bottom of your library in any order.

Flying
Ride {3}{U} ({3}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

When Duncaster Nightwatcher enters and whenever you cast a noncreature spell, create a 1/1 colorless Human creature token.
Whenever you attack with three or more creatures, return target noncreature, nonland card with mana value 3 or less from your graveyard to your hand.

At the beginning of your end step, draw a card for each card you drew this turn.

Flash
When Elusive Illusionist enters, target attacking creature gets -2/-0 until end of turn.

{1}{U}: Exile Elusive Monkey. Return it to the battlefield under its owner's control at the beginning of the next end step.

Harmony — Draw a card.
When Enthralling Actor enters, harmonize. (Trigger up to one harmony of one permanent you control.)

When Esiara, Skycaster's Infiltrator enters, exile target spell with mana value 4 or less.
{1}{U}{U}, Discard two cards: Exile Esiara, then return it to the battlefield under your control.
{2}{U}{U}, {T}, Exile Esiara: Until end of turn, you may play cards you don't own from exile.

When Exquisite Artisan enters, judge target noncreature artifact you control. If you honor it, it becomes a 0/0 Construct artifact creature with flying. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

{U}, Discard a card: Counter target spell unless its controller pays {1}.
Whenever a spell or ability you control counters a spell or ability, you get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

Flying, ward {2}
Whenever Faraway Albatross attacks, choose one —
• Faraway Albatross gets +1/+1 until end of turn for each spell you've cast this turn.
• Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

When Field Technician enters, you may search your library for an artifact card, reveal it, then shuffle and put that card on top of it.
Artifact creatures you control get +1/+1.

Flying
When Fleeting Distractor enters, sacrifice it unless you return another creature you control to its owner's hand.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever Gentleman Thief deals combat damage to a player, gain control of target marked creature.

Whenever Gifted Warmage attacks, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• Flying

Flying

When Gleeful Deviser enters, create a 1/1 colorless Construct artifact creature token.