Dan'Kaar, Grim Researcher

+1: Reveal the top card of your library. If it's a creature card with converted mana cost 2 or less you may put it onto the battlefield.
-2: You may sacrifice a creature. If you do, draw two cards.
-5: Return each creature you control with converted mana cost 2 or less to its owner's hand, then destroy all creatures. They can't be regenerated.