Thor, God of Thunder

Thor has flying if he is equipped with Mjolnir, Hammer of Thor.

When Thor enters the battlefield, you may search your library and graveyard for Mjolnir and put it on to the battlefield attached to Thor.

I Say Thee Nay— During combat, after blockers have been assigned but before damage is dealt, you may pay {x}, where {x} is equal to Thor's power. If you do Thor gains trample and +{x}/+{x} where {x} is equal to mana spent to cast this ability, until end of turn.