Bone Armor (DN)

A score of bone shards orbit the caster, reinforcing her defenses by granting 10 temporary hit points. When a melee attack strikes the barrier for enough damage to destroy it, the attacker - if adjacent - is choked by necrotic gases as the barrier discharges part of its energy, and makes its next attack roll with disadvantage, if done before the end of its next turn.

The spell ends if the temporary hit points are depleted, or if you dismiss the spell as an action.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the caster's temporary hit points increase by an additional 5 for each slot level above 1st.