Waves of Fatigue

Waves of negative energy wash over all living creatures in the area of effect.  Creatures that have unusual physical features, are immune to stun or paralytic effects, are immune to critical hits or at the DM’s discretion are unaffected by this spell.  

Creatures that start their turn in or enter the area of effect for the first time must make a CON saving throw.  Failure indicates that they gain 1 level of exhaustion.  After 5 failed saves the target dies (5 levels of exhaustion).