God-Pharaoh's Devotee

Whenever God-Pharaoh's Devotee becomes blocked, defending player sacrifices a creature.
Whenever God-Pharaoh's Devotee attacks and
isn't blocked, blue, black, and red spells you cast cost {1} less to cast until your next turn.
Teleport {1}{u}{b} ({1}{u}{b}: Exile this creature, then return it to the battlefield under its owner's control.
You can't activate this ability if this creature entered the battlefield this turn.)