Threats Must Be Destroyed!
"And even then, if my true body were to appear in the world, I would be directly destroyed by the Heavenly Dao," the old man sighed, though it seemed like invincibility was a blessing.
But he cannot enjoy such a blessing in Lower Verse
Tian Shen found his situation a bit funny, in terms of logic, this old man is the most powerful entity in the Lower Verse, but if even his real body appears in the world, he would be directly destroyed by the Heavenly Dao.
As for why he doesn't ascend? Apart from the fact that some terrifying beings in the Upper Verse have some problem with him, the Heavenly Dao does not allow him to do so
This old man is like an employee of the Heavenly Dao, he is responsible for protecting the Lower Verse in certain situations such as the attack of the darkness or the innate demons race.