Cloak of Doom

You become cloaked in abject darkness, the dreadful energy leeching the life of anything that dares draw close. While this spell is active, you deal an additional 1d6 necrotic damage with weapon attacks and cast a deep shadow in a 10 foot radius around you and you gain resistance to necrotic and radiant damage.

When you cast this spell, you can designate any number of creatures you can see to be unaffected by it. Affected creatures that enter the radius for the first time or end their turn there take 1d6 necrotic damage.