Vitriolic Sphere
4th-level evocation
Casting Time: 1 action
Range: 150 feet
Components: V, S, M (a drop of giant slug bile)
Duration: Instantaneous
You point at a place within range, and a glowing 1-foot diameter ball of emerald acid streaks there and explodes in a 20-foot radius sphere. Each creature in that area must make a Dexterity saving throw. On a failed save, a creature takes 10d4 acid damage and another 5d4 acid damage at the end of its next turn. On a successful save, a creature takes half the initial damage and no damage at the end of its next turn.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the initial damage increases by 2d4 for each slot level above 4th.