Gaurdians of the Peace

Foreign (This creature can only be cast from your graveyard or exile by paying its converted mana cost.)
Tap an untapped creature you control: Prevent all damage that would be dealt to creatures you control until end of turn.
{w/b}{w/b}{w/b}{t}: Each opponent loses life equal to the number of Cosmic creatures you control. You gain life equal to the life lost the way.