Tanuuma Berserker

Trample, Haste.
Whenever Tanuuma Berserker attacks, you may
reveal cards from the top of your library until
you reveal a creature card. If you do, until end of
turn, creatures you control assign combat damage
equal to that card's converted mana cost rather
than their power, then shuffle all cards revealed
this way back into their owner's library.

"THUD!! And neither of them survived..."