Warded Battlements

Defender (This creature can't attack.)
Attacking creatures you control get +1/+0.

Barrin, Tolarian Archmage

When Barrin enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Cancel

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Discontinuity

During your turn, this spell costs {2}{U}{U} less to cast.
End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Enthralling Hold

Enchant creature
You can't choose an untapped creature as this spell's target as you cast it.
You control enchanted creature.

Aven Gagglemaster

Flying
When this creature enters, you gain 2 life for each creature you control with flying.

Frantic Inventory

Draw a card, then draw cards equal to the number of cards named Frantic Inventory in your graveyard.

Frost Breath

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Ghostly Pilferer

Whenever this creature becomes untapped, you may pay {2}. If you do, draw a card.
Whenever an opponent casts a spell from anywhere other than their hand, draw a card.
Discard a card: This creature can't be blocked this turn.

Jeskai Elder

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever this creature deals combat damage to a player, you may draw a card. If you do, discard a card.

Keen Glidemaster

{2}{U}: Target creature gains flying until end of turn.

Library Larcenist

Whenever this creature attacks, draw a card.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

Mistral Singer

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Core Set 2021