Aura of Demise

You cause dark, deleterious energy to swirl around you in a 10 ft. radius. This aura moves with you, and is centered on you.

Until the spell ends, each hostile creature within range that starts its turn in the area, or moves into the area for the first time on its turn must make a Constitution saving throw. On a failure, an affected creature has vulnerability to all damage until you or an ally of yours hits an affected creature with an attack, at which point the effect ends for that creature.