Onion
4th-level Necromancy (Wizard)
Casting Time: 1 action
Range: 60 feet
Components: V, S, M (an onion the caster must peel during the casting)
Duration: Concentration, up to 1 minute.
You point at a creature you can see within range, and begin peeling an onion. The target must immediately make a Constitution saving throw against your spell save DC. On a success: The target takes 3d6 necrotic damage, and the spell ends immediately. On a failure: The target takes 6d6 necrotic damage.
While the spell lasts, at the start of each of the target's turns, it must make a Constitution saving throw. On a failure, the target takes an additional 3d6 necrotic damage and gains one level of exhaustion. On a success, the spell ends.
Once a creature has gained three levels of exhaustion from this spell, the spell ends.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the initial damage increases by 1d6 for each slot level above 4th.