Tianyue's death was strange. He had a high fever for three days inexplicably and then he told the world. But Tian Yue has a weak temper, and he doesn't care if he dies.
Time travel? He doesn't want to. He's already dead, why bother going to another world?
Reincarnation? Although he only lived for twenty-five years, he didn't miss the human world too much.
It's better to just stay in the underworld and be a god of death, catching ghosts and collecting demons, and you'll be free and at ease.
Conception: