Hero X Demon King X Villain

A noble ‘hero’ who punishes evil with the protection of the gods. A powerful demon born with the power of the devil, the last surviving ‘Demon King’. A skilled third-rate ‘villain’ who moves around an evil organization. The villain’s life is now over. I was planning on retiring and spending the rest of my life comfortably, but, the guy who I accidentally picked up was the Demon King. And now, the hero is coming to me to repay a favor, ruining my comfortable retirement life! Ninety-nine demons protecting the villains…