Diaborus, Cavern of the Cursed

You may pay {w}{u}{b}{r}{g} rather than pay the
mana cost for spells you play. If you do this, you
gain a curse counter.
{t}: Choose one: Create a 1/1 Demon token with:
Sacrifice this creature: Destroy target permanent,
you gain a curse counter (A player with 5 or
more curse counters loses the game.); or add {b} to
your mana pool.