As he traveled all the way, Fisher had already learned from different places about the deeds committed by the gods, thus forming his current thoughts.
The gods indeed committed unforgivable crimes...
The gods stole precious treasures, that should count as one; the gods betrayed the Divine of the Outer Realm invasion, that should count as two; the gods imprisoned He Weng's sister, He Ya, turning her into a tool to fulfill the rules of Death, that is three.
Anyone with insight can see that this doom was caused by the sins committed by the gods, Fisher knows this better than anyone.
Although Fisher is determined to fight to resolve the Doomsday Prophecy, it is certainly not for these gods, especially since along the way, the gods have ignored everything, hiding behind the scenes like an idle manager, leaving everything to the living creatures of reality and throwing the burden onto Fisher; this makes Fisher find it even harder to trust Ramasitia.
