This spell costs less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!
The ability that reduces the mana cost only reduces its generic mana cost. It will cost at least {B}{B}{R}, even if more than eight creatures have died this turn.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.