Exhaustion

When you cast this spell you select 1 creature, they must make a con save or gain 1st level exhaustion. You can only cast this on a creature that doesn't have exhaustion already, unless you are upping it up to a different level. Spell can be broken with 8 hours of sleep or one full day cycle.

when casted at a higher level it increases the level o exhaustion by 1 level per spell level casted.