Accidentally Attacked a Great Demon King

Han Zhiyuan never expected that a trip to mountain to watch sunrise would make him bring back a demon king home. His first reaction when he heard a voice in his head was:
“Its over, I’ve been possessed”.
Demon King: Ant, if you don’t retrieve the remnants of this king’s scattered souls from different worlds, this king will kill you! Make your soul scatter!
In short, the demon king can kill him just by blowing his breath.
So Han Zhiyuan was forced to embark on a journey to awaken the remnant souls of the demon king. But how to awaken the remnant souls of the demon king?
The demon king is cruel and ruthless by nature. The only way to awaken the soul is by making them feel true emotion.
So the only way is, “Let the remnant souls fall in love with me”?
Han Zhiyuan: Can this get anymore bloody?
The demon king raised his eyebrows: Huh?
Han Zhiyuan: I will do my best.