Miyu, the Scorching Claw

Haste, trample
Whenever Miyu attacks, exile the top card of
your library, then choose one:
• Miyu gets +X/+X until end of turn, where
X is the converted mana cost of the exiled card.
• You may play that card this turn. If it's
noncreature spell, it costs {1}{r}{g} less to cast.