Cloak of Istishia

As you cast this spell, a dark storm cloud covers you and your gear, shielding you from coming attacks with the power of lightning. You gain 5 temporary hit points for the duration. If a creature hits you with a melee attack while you have these hit points, the creature takes 5 lightning damage.

At higher level: When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points and the ligthning damage increase by 5 for each slot.