Crooked Hierophant

Demon spells you cast cost {1} less to cast.
{3}{b}{b}, {t}, Exile 3 nondemon creatures you
control : Create a 5/5 black Demon creature
token with Flying and each ability of each
creature exiled as part of the cost to activate this ability.
"I will serve you to my last breath. You will take
down their false gods."