Keythriglos, Vile Glutton

Ogre Offering (You may cast this card any time you could cast an instant by sacrificing an Ogre. If you do,
the total cost to cast this card is reduced by the sacrificed permanent's mana cost.)
Whenever an Ogre you control dies, Demons you control gain indestructible until end of turn.
At the beginning of your end step, if no Ogres you control died this turn, put a -1/-1 counter on each Demon you contro