Volatile Blood Barrier

You conjure quivering ethereal blood to make a thin shield around you. You gain 3d8 temporary hit points. When the temporary hit points granted by this spell are lost, all creatures within 10 feet of you must make a Dexterity saving throw or take 2d10 acid damage, and the spell ends.

You can use a bonus action on your turn to lose all temporary hit points you have gained from this spell.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage dealt is increased by 1d10 for every level above 2nd.