- MC transmigrated into a demon world/underworld (or something like this) - The original owner of the body had a very high status in the human world, but was a weakling (I think he was schemed against and ended up dying in the demon world) - Every couple hundred years (I think), there is a war between the demon and human world. - After transmigrating, the MC ends up as an experiemental subject to an alchemist. - The alchemist and MC ended up as teacher and pupil/ friends - MC helps out a noble demon family and the head of the family is a very young lady, who falls in love with MC. Her sister also falls in love with MC (I know, eye roll) - The MC made a pact with a dragon I hope someone can help me out with this.