Voodoo

You lock eyes with a target within range. They must succeed on a constitution saving throw or they are engulfed in black necrotic energy. After emerging from this energy the target is left looking and feeling the same but any damage taken by the caster is instead dealt to the target. Attackers must succeed on a DC15 perception check after attacking the caster to realise the spells effect. If the target attacks they know immediately the spells effect after doing damage.