The first option he has at his disposal is to use the small world that Lady Red plans to use to create her divine position. The second option is to use the small world that has been prepared as the Heavenly Battlefield.
The first option will require him to find a way to find the small world and travel to that small world. After all, the small world is outside the Blessed Heaven World. It is not in a place nearby that he can stroll to.
He is inclined to pick the second option for this reason and because he won't have to fight the will of the world and the world king in the Heavenly Battlefield. Since the second option is so accessible and was of less difficulty, it wasn't difficult for him to pick this option.
So when he successfully reversed time and reappeared in the physical world, the first thing he did was to become an inner sect disciple and register for the Heavenly Battlefield mission.
