Akujo Kyousei Keikaku

"Hey, Seraphina. Even when you grow up, don't end up killing me, okay?" The wizard Arvel meets his end at the hands of his former fiancée, Seraphina, who would later become the emperor's mistress and a notorious villainess. However, when he comes to, he finds himself face-to-face with a young Seraphina! Astonishingly, he has returned to being his 13-year-old self. Seeing Seraphina before she becomes a villainess, Arvel makes a resolution: he will raise her to become a proper person and save his own life. To start, he begins searching for a way to prevent the death of his brother, Shou, who was once engaged to Seraphina. However, the situation is far from simple, as he must contend with Seraphina's neglectful family, men vying for the beautiful Seraphina's attention, and a web of conflicting intentions. In this journey through time, can Arvel alter Seraphina's fate and save her from becoming a villainess...!? (Source: Bushiroad, translated)