Roduun, Beast of Unburial

For every card you discard, Roduun, Beast of
Unburial cost {1} less to cast
Flying
{2}{r}, Discard a card: Each player loses life equal
to that cards converted mana cost.
{b}{b}, {t}: If you dealt combat damage this turn
return to the battlefield all creature cards in your graveyard that were put there from anywhere this
turn.