Echidna's Tiring Pursuits

You trick the target's body and mind into feeling more tired than it actually is, resulting in a sluggishness that lingers until they rest. The target must make an Intelligence saving throw, taking 1d4-1 (minimum of 1) levels of Exhaustion on a failed save or disadvantage on their next attack roll on a successful save.

If the target is immune to Exhaustion, they instead take 4d12 Psychic damage.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the psychic damage increases by 1d12 for each slot level above 5th.