Siriath, Herald of the Storm

Flying, haste

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

Whenever Siriath attacks, it deals 3 damage divided as you choose among one or two targets.

Whenever Siriath deals combat damage to a player, you may discard a card. If you do, draw a card.

"Born from the tempest and the blaze, its wings crackle with thunder and flame, heralding the storm."