Enervating Shield

4th-level necromancy

Casting Time: 1 action

Range: self

Components: V, S, M (a bit of rotten organic matter or bone dust)

Duration: 10 minutes

A miasma of fog like cold wreathes your body for the duration, obscuring vision in a 20-foot radius. You can end the spell early by using an action to dismiss it.

Whenever a creature within 10 feet of you hits you with a melee attack, the shield drains life from them. The attacker takes 2d8 necrotic damage and you gain temporary hit points equal to half of the damage taken, round down.