Vampiric Sphere

The air around you becomes darkened and is changed into a hungering aura. For the duration of the spell, all chosen creatures that enter or start their turn within a 30 foot radius of you must make a Constitution saving throw. If failed, they take 6d8 necrotic damage, or half of much damage on a successful save. You gain an amount of hit points equal to half the necrotic damage dealt. The aura is centered on you, following you as you move and moves around corners. The spell does not effect undead or constructs.