Altar of Dementia [Modern Horizons] Commander's Arsenal Does them some good if

Does them some good if we smash every one so often

If this card destroys your opponent's monster as a result of battle

Special Summon 1 “Harpie” monster from your Deck in face-up Defense Position

Set: Ninth Edition Type: Creature — Spirit Rarity: Rare Cost: {3}{G}{G} Untap all permanents you control during each other player's untap step

Altar of Dementia [Modern Horizons] Commander's Arsenal Does them some good ifSet: Modern Horizons Type: Artifact Rarity: Rare Cost: {2} Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power. "It is not that you will go mad. It is that you will beg for madness." Volrath