Boros's Empty Throne

{p/c}{p/r}{p/r}{t} you may gain double the life you payed to activate this ability if you discard a card for every 2 life lost
{p/c}{p/w}{p/w}{t} you may gain double the life you payed to activate this ability if you give target creature you don't control +2 +2
{p/c}{p/b}{p/b}{t} you may gain double the life you payed to activate this ability if you sacrifice a creature