Fatigue is a mid-level demon from the Actraiser universe and a boss fight in Arctraiser 2 - it resembled in many ways a skeletal "grim reaper" riding a giant cloud with a face: the cloud could attack via blowing out boomerang-like projectiles when confronted.

Fatigue was corrupting Dilligence using cursed rainfall from the cloud, which made men grow apathetic not only towards right and wrong but also against life itself - this inbalance could not be tolerated by The Master (originally God in the Japanese title, changed in the English translation into an archangel).

Thus the Master came down and fought Fatigue as part of his quest to rid the world of thirteen powerful evils that were unleashed by his eternal nemesis, Tanzra (who was originally Satan but was again changed for an English audience).