Agent of Erebos
Agente de Érebo
Agente de Erebos
Enchantment Creature — Zombie
Constellation — Whenever Agent of Erebos or another enchantment enters the battlefield under your control, exile all cards from target player's graveyard.
The constellation ability is mandatory. If you are the only legal target (perhaps because your opponent has hexproof), you must target yourself and exile all the cards from your graveyard.
An Aura spell without bestow that has an illegal target when it tries to resolve won’t resolve and will be put into its owner’s graveyard. It won’t enter the battlefield and constellation abilities won’t trigger. An Aura spell with bestow won’t be countered this way. It will revert to being an enchantment creature and resolve, entering the battlefield and triggering constellation abilities.