The World Went Back, but I Unexpectedly Retained My Memory

[Mortal flow, rebirth, no system, no harem, decisive killing, protagonist with a sinister background] My name is Wen Changsheng, and I was reborn into a world where I can cultivate immortality. However, after hearing the news in the evening, he died in the morning. That's right. You read that right. That is, he attained enlightenment that night, but died that morning! Quite contradictory, right? Then let me tell you that the "time" of this world has been manipulated. Do you still feel conflicted?