Betsuyou Kokurenge Koutei Toutaishin: Bad End Kaihi no Tame no Haraguro Koutei Ikusei Keikaku

Lin Ruoxuan is reincarnated into the world of his favorite historical novel. His assigned task is to eliminate Ji Ruxue, who will later grow up to be a tyrant and oppress the protagonist. However, unable to bring himself to do it, Lin Ruoxuan decides to become Ji Ruxue's tutor (a fake eunuch) and raise him into a "wise ruler." Can he prevent tragedy? What fate awaits the boy, whose eyes are filled with twisted love and obsession...? Source: MU