After Hundreds of Lives, I Am Still a Young Man.

The protagonist Rufeng is not a genius in the traditional sense, but a "hundred-generation banished immortal" under the laws of heaven. In order to repair a plane that was about to collapse, he was forced to go through hundreds of reincarnations. In each life, he needs to seal his memory and experience life, old age, illness, death, love, hate, and separation as a mortal. After returning from a hundred lifetimes, although he regained his supreme cultivation, the vicissitudes and fatigue of hundreds of lifetimes were engraved deep in his soul. Only his obsession with his "original intention" kept him in the state of mind of a young man.