The Middle Stage.

"Can we not do anything to him?" A celestial god asked sullenly.

"No, there's nothing we can do but hope for the best. The challenges in the middle stage are random. It can be a short trip or it can be a long one. But he will have to face at least one of you before he can reach the final stage. So you must kill him then."

Ode didn't design the middle stage of the final stage. There were set instructions within the dungeon core that were executed to create those stages. Only in the first stage was he permitted to modify a little. So the gods don't have any control over the mechanism of the middle stage.