Rageform

Wutform (Rageform) (de)

Enchantment (CMC 4)
When Rageform enters the battlefield, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Rageform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)