Hecate, Demonic Bride

Whenever Hecate, Demonic Bride, or another
warlock or demon enters the battlefield under
your control, each player exiles the top card of
their library. You may cast noncreature spells
exiled this way for as long as they remain exiled
using mana as though it were mana of any color.
{u}{b}{b}{r}, {t}, sacrifice three other creatures:
create a 4/4 black demon creature token with
flying, lifelink and prowess. Activate this ability
only any time you could cast a sorcery.