Thunderheads

Flying Whenever you draw a card, Niv-Mizzet deals 1 damage to any target. T: Draw a card.

Whenever you cast an instant or sorcery spell, this creature gets +3/+0 until end of turn.

Instant and sorcery spells you cast cost 1 less to cast.

(U/R can be paid with either U or R.) 2U: Copy target instant spell you control with mana value 2 or less. You may choose new targets for the copy. 2R: Copy target sorcery spell you control with mana value 2 or less. You may choose new targets for the copy.

T: This creature deals 1 damage to any target. Whenever you cast an instant or sorcery spell, you may untap this creature.

Flying Whenever you cast an instant or sorcery spell, this creature gets +2/+0 until end of turn.

When this creature enters, if R was spent to cast it, it deals 2 damage to any target.

Target player shuffles their graveyard into their library.