Asha, Titan of Smoke

Asha, Titan of Smoke enters the battlefield tapped
unless you sacrifice another spirit or elemental.
Haste, menace.
When Asha attacks, exile the top card of your
library. Asha gets +X/+X until end of turn,
where X is the exiled card's mana value.
You may play cards exiled by Asha for as long as
they remain in exile.