"I am the purifier, the light that clears all shadows."
—Seal inscription

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Murders at Karlov Manor Commander

Modern Horizons 2

"Find the dens of evil and flood them with light."
—Hulo, the Penitent Wanderer

The List

Eternal Masters

Commander 2015

Sacrificing Seal of Cleansing is the cost to activate its ability. Once you activate the ability, no player can do anything to Seal of Cleansing to stop you from activating it. Notably, if you cast Seal of Cleansing during your turn, you'll have priority to activate its ability before anyone can respond to stop you.