Acid Barrier

You surround yourself with a sphere of acid. You gain 30 temporary hit points. You can't make weapon attacks through the sphere. Any acid damage that would be dealt to you while you have these temporary hit points increases the amount of temporary hit points you have by the amount of damage that would have been dealt, not going above the initial amount of temporary hit points.

While you have these temporary hit points any creature that makes a melee attack against you takes 1d4 + your spellcasting modifier acid damage.

On you turn, as an action, you may sacrifice 5 of the temporary hit points to make three ranged spell attacks against a single target that each deal 1d4 + your spellcasting modifier acid damage (range 30ft). If you have less than 5 temporary hit points left you may sacrifice all of the remaining temporary hit points to do this instead.

At higher levels. When you cast this spell using a spell slot of 4th level or higher the temporary hit points you gain increases by 10 for each slot level above 3rd. At 5th and 6th level the damage die increase to d6. At 7th and 8th level the damage die increase to d8. At 9th level the damage die increase to d10.