Vengeful Friend

You summon a spectral ally within 5-ft of you to punish your enemies and shield you from attack. The spirit stays in its space for the duration of this spell, granting you half-cover while you are within 30-ft of it. Whenever you are damaged by an attack or harmful spell, roll 1d6. The damage you take is reduced by that amount, and if your attacker ends its turn within 30-ft of your spirit, your attacker takes necrotic damage equal to the amount deflected. Your Vengeful Friend can deflect a number of attacks equal to 1 + your spellcasting ability modifier, after which it vanishes and this spell ends. 

At higher levels: For each spell slot higher than 2nd, you can add an extra 1d6 to the damage your Vengeful Friend can deflect. If you cast this spell at 5th level or higher, it provides three-quarters cover instead of half-cover.