Ghost, an S-rank Mercenary who often took on assassination jobs had been killing and fighting for as long as he could remember, constantly contemplated the life he could have led had he just gone to the Royal Academy instead of becoming a mercenary at 16. Thirty years after his choice, all he had was an empty life with full pockets, never going hungry, but never settling down either.  When a request comes in for S-ranks specifically, issued by the Crown Prince of the Holy Empire, there was no way Ghost was going to turn it down, especially when he saw the hefty reward. However, after finding out about the details of the request, things got more dangerous than he had ever imagined. Death, that was the only thing awaiting him at the end of the request, at the hands of Demonic forces unlike anything he had faced before. Dreaming of the life he could have had while on his deathbed, Ghost miraculously finds that he is still alive, but something isn't quite the way it had been a moment ago.