Return target creature to its owner's hand.

Steamveil Model enters with a +1/+1 counter on it.

Whenever you cast an instant or sorcery spell, Skyward Magus gets +1/+1 and gains flying until end of turn.

Counter target spell unless its controller pays {4}. You may untap a land.

Target creature gets +2/+0 until end of turn and can't be blocked this turn.

Scuttle Tank enters with a defender counter on it.

Target creature gains flying until end of turn. Draw a card.

Runway Mech enters with a +1/+1 counter on it.

Counter target spell with mana value X. If that spell is targeting you or a creature you control, you may choose new targets for it instead.

Choose one —
• Draw two cards.
• Put a +1/+1 counter on target creature, scry 1, then draw a card.

Choose one or both —
• Return target creature to its owner's hand.
• Return a creature with the greatest power or tied for the greatest power to its owner's hand.

Gain control of target nonland permanent until end of turn. Untap it. Then you may pay {2}. If you do, gain control of that permanent until the end of your next turn.

Flying
Creatures you control but don't own get +1/+1 and have flying.
Whenever a creature you control deals combat damage to a player, you may return it to its owner's hand.

Sacrifice a Treasure: Put a loyalty counter on Marilye, Dreaming Big.
[+1]: Draw a card, then discard a card. If you discarded a nonland card this way, create a tapped Treasure token.
[–3]: Gain control of target artifact. It becomes a Treasure artifact, loses all other types, and loses all abilities except for activated mana abilities.
[–8]: Target opponent chooses a nonland permanent they control. You gain control of the rest.

Put a +1/+1 counter on target creature. It gets +0/+2 until end of turn.

At the beginning of your end step, scry 1. Then if it's your first turn of the game or you discarded a card named Leystone of Depths this turn, draw a card.
Cycling {U}

Exile target creature you control, then return that card to the battlefield under its owner's control.

Flying
Discard a card: Put a +1/+1 counter on Jetstream Cruiser. Activate only once each turn.

Put a defender counter on each creature.

Return target creature to its owner's hand. If you've cast another instant or sorcery spell this turn, draw a card.

{1}{U}, {T}, Sacrifice Emulation Expert: Gain control of target creature you don't control with mana value 3 or less. Its owner creates a tapped token that's a copy of it. Activate only as a sorcery.

Whenever Defthand Infiltrator deals combat damage to a player, put a +1/+1 counter on it if it doesn't have one on it.
Defthand Infiltrator can't be blocked as long as it has a counter on it.

Whenever Deeptreader Arcanist attacks, you may draw a card. If you do, discard a card.

Flying, ward {1}
Whenever you cast an instant or sorcery spell, mill a card. Return an instant or sorcery card milled this way to your hand. If you can't, put a +1/+1 counter on Covetous Frostwyrm.

Enchant creature
When Contain for Study enters, tap enchanted creature.
You control enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.