Driffa's Glacial Guard

A protective barrier of magical ice surrounds you until the spell ends.

Your base AC becomes 12 + your Dexterity modifier. In addition you gain 10 temporary hit points which refresh every 10 minutes. If a creature in melee range hits you and deals damage which is completely absorbed by this spells temporary hit points they take cold damage equal to the damage they dealt. The spell ends if the target dons armor or if you dismiss the spell as an action. For each lv higher than second for which this spell is cast, the temporary health increases by 5.