Seth, a 23 years old man, died saving the life of children caught in a fire.

He reincarnated as a powerful Demon, and the rigt arm of the demon lord

However he fell in love with one of the member of the heroes party?!

P.s. I took the inspiration from a LN for the base of the story but it's only for the first few chapter

P.s2. I'm bad with romance stuff so it might be bad sorry in advance