Cause Fatigue

You forcefully release energy out of one creature you can see. That creature must make a Constitution saving throw against your spell save DC or gain one level of exhaustion for one hour. After the hour is over, the energy you pulled from them flows back into their body. You cannot cast this spell on the same creature again until a day has passed.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the level of exhaustion increases by one for each slot level above 3rd. If you choose to cast this spell at 8th level or higher, the stress severely weakens you. Each time you cast a spell until you finish a long rest, you take 1d10 necrotic damage per level of that spell. This damage can't be reduced or prevented in any way. In addition, your Strength drops to 3, if it isn't 3 or lower already, for 2d4 days. For each of those days that you spend resting and doing nothing more than light activity, your remaining recovery time decreases by 2 days.
Classes

• Wizard

Level: 3rd
Casting Time: 1 Action
Range/Area: Sight
Components: V, S
Duration: Instantaneous
School: Evocation
Attack/Save: CON Save
Damage/Effect: Exhaustion