I'm the Mysterious Leader of the Salvation Organization - Chapter 557:

[Unique Trait – Those you meet will remember you. No matter what happens, they will remember you forever.] In a world on the brink of ruin, people summoned to save it are categorized as heroes and extraterrestrial workers, abbreviated as “foreign workers.”For some reason, I became a foreign worker who is loved by transcendents that view humans as mere insects.

After annihilating Han, Zhao and Wei empires in succession, the dynasty of Qin is ushering in an unprecedented flourishing age with powerful cultivators emerging endlessly. People take pride in being part of the Qin dynasty. However, Ding Ning, a young lad of humble origin in Changling, Qin, is determined to subvert this dynasty and kill the emperor who breaks in the Eighth Realm.

- Description from Novelupdates

Seven years ago, after their breakup, he disappeared without a trace.

After rebirth, Long Xiaoyuan went into raptures because he was in poor health in his previous life. However, he suddenly found that his soul was in the body of a fatuous and self-indulgent emperor.