100 Ways to Heal a Psychopath
https://www.cocomanhua.com/17052/ Mc was a cat demon (yao guai or in Japanese- youkai) he was picked up by the ML on his trip to the human realm. Ml is the Heavenly Emperor, and they were forced to separate because ML mistakenly thought that MC was a possible threat. But he already liked MC so much that instead of killing him, he sent him to the demonic realm for the YaoGuais/Youkais . The only way MC can ever meet ML again is if he were to cultivate to become a god. So he did. When he finished cultivation in the demonic realm, he needed to succeed in 3 trials. Each trial was to reincarnate as a human and suffer 3 separate "hardships" in each life. MC forgo the last trial because he thought that ML never loved him/incapable of love. So he went back into the reincarnation loop and forgo all his memories and efforts. Then some more heart-wrenching stuff. But ML did truly fell in love with MC. He gave MC part of his powers which let MC become a god in the start of the story. He gave MC part of his power despite the possibility of dying and losing his godship(?).
Komatta Toki Ni Wa Hoshi Ni Kike!