I thought you were asking if the main character had reincarnated, not if they were going to reincarnate as a devil. Another thing: the story will be long and many things will happen, some good for the main character and some not so much.
It's someone from our world who's in Riser's body. Although they have the memories of the original Riser, he won't accept anyone from his family disrespecting him, even if it's his father. Victorius was the one who attacked first.