Obelisk, the Tormentor

Offering 12. (Instead of paying this spell's mana cost, sacrifice three creatures with total mana value 12 or more.)

Hexproof.

{t}, sacrifice two creatures: destroy all creatures your opponents control. Deal damage equal to Obelisk's power
to target opponent.

If Obelisk, the Tormentor is cast or put on the battlefield without paying its offering cost, sacrifice it during the end phase.