EmVP, Avenger's Fist

Whenever a non-Hero creature you control attacks, look at the top seven cards of your library.
You may put any number of Hero creature cards from among them onto the battlefield tapped and attacking. They gain indestructible until end of turn.
Put the rest of the cards on top or on the bottom of your library in any order.

“With every strike, his fist carries the will of Earth’s mightiest heroes.”