Fatigue is a demon of Tanzra, and is causing the downfall of Diligence. He awaits in Industen.
Based on the Deadly Sin of Sloth, Fatigue resembles a gigantic snail, and attacks by raining down debris on the Master and firing lasers from his antennae. A Nintendo Power review mistakenly listed a different unnamed demon boss as Fatigue, which still causes confusion among players. Fatigue reappears as the first boss in Deathheim.