msem-instigator

Return target creature to its owner's hand. You may have another target creature gain flying until end of turn.

Flying
Instant, sorcery, and Wizard spells you cast cost {1} less to cast.

(Transform this if it's not attached to a creature. Pay {3}{U} as a sorcery to unattach it.)
Enchant creature you control
Gamhaugen Warbeast's rider gets +2/+2 and has flying.

Pressure {1}{U}{U} (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Draw three cards.

Enchant opponent
Enchanted player plays with the top card of their library revealed.
Whenever enchanted player casts a spell, you may have them mill a card.

Choose flying, prowess, vigilance, or ward {2}. Create a colorless Equipment artifact token with “Equipped creature has the chosen ability” and equip {2}. (Then exile this card. You may cast the creature later from exile.)

Draw two cards.
You may cast an instant or sorcery spell with mana value 3 or less from your hand or graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

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 Gentry Infiltrator deals combat damage to a player, you may search that player's library for a creature card and exile it. If you do, that player shuffles.
{2}{U}{U}: Gentry Infiltrator becomes a copy of a creature card exiled with it until end of turn.

Target permanent phases out. (Then exile this card. You may cast the artifact later from exile.)

Flying
Creatures your opponents control get -1/-0.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Whenever Ghostly Hounds mentors a creature, that creature can't be blocked this turn.

Whenever you cast a spell during an opponent's turn, put a charge counter on Gift of the Sphinx.
At the beginning of your upkeep, draw a card for each charge counter on Gift of the Sphinx.

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

Create a 2/2 colorless Spirit creature token.
Draw a card.

When Gilded Authority enters, create two Treasure tokens. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)
Creatures your opponents control get -1/-0.

When Gitaxian Reprocessor enters, if you cast it, choose one —
• Create a token that's a copy of another target creature, except it's an artifact and isn't a creature.
• Create a token that's a copy of target noncreature artifact, except it's a 2/2 creature in addition to its other types.

You may pay {U} and tap an untapped Rogue you control rather than pay this spell's mana cost.
Counter target spell unless its controller pays {2}.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Untap each Horror you control during enchanted creature's controller's untap step.

Flying, prowess
{T}: Until end of turn, target land is every basic land type in addition to its other types.

Harmony — Target creature gains flying until end of turn.
When Glamorous Aerialist enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Flying

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Gleaming Rider envisions an instant or sorcery card, target creature becomes a 5/5 Elk Spirit until end of turn.