Fukushuu no Tensei Kizoku ~Subete o Ubawareta Daikenja, Onore o [Fukusei] shite Nidome no Sei o Eru~

Getting revenge against rotten nobles who are power-hungry! A dark fantasy is about to unfold! In a world where abusing prisoners of war is considered normal, there was a genius mage named Rein who was bestowed the title of "Great Sage" despite being born as a prisoner. However, that prisoner along with his land and fame that he obtained, was nothing but thorn in the side of the nobles that needed to be purged. Rein, who was set up and killed mercilessly, used his magic to duplicate his own soul. He then reincarnates as the son and heir of his sworn enemy, and swears revenge against the nobles that killed him! Come, it's purging time.