Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Snap

Return target creature to its owner's hand. Untap up to two lands.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Thought Scour

Target player mills two cards.
Draw a card.

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Eris, Roar of the Storm

This spell costs {2} less to cast for each different mana value among instant and sorcery cards in your graveyard.
Flying, prowess
Whenever you cast your second spell each turn, create a 4/4 red Dragon Elemental creature token with flying and prowess.

Rewind

Counter target spell. Untap up to four lands.

Reinterpret

Counter target spell. You may cast a spell with equal or lesser mana value from your hand without paying its mana cost.