The Regressed Son of a Duke is an Assassin

Cyan Vert, the best assassin of the continent, meets a pitiful death after having been betrayed by his own brother, whom he had trusted all his life. If I were given another chance at life, I would live it differently. I would only trust myself, and achieve all the things I want on my own without serving anyone else but myself. That is how I was given a second chance at life. The Cyan Vert, a shadow who lived for others, is no more. I will now pave a path on my own, for myself!The Regressed Youngest Son Of The Duke Is An Assassin, 회귀한 공작가의 막내도련님은 암살자