The Black Book: Seven Deadly Sins - Chapter 25: A Strong Addiction to Being Mediocre

Liu Duo was a young girl whose grandmother sold her to four brothers with the intent to be a bride. Unwilling, she ran away the following night, only to fall unconscious while trying to get away. Unexpectedly, however, she was reborn with the spirit of a 25 year old woman, also named Liu Duo.

- Description from Novelupdates

The handsome, noble, cold, and ruthless family heir Ignatius Leclair took a liking to the fostered girl Delphine Carter in his home.From then on, the aloof man transformed into a loyal companion, taking care of children, cooking... The entire aristocratic circle was utterly shocked, with everyone envying.Delphine Carter smiled serenely: cunning, energetic, vengeful, a different persona by day and night.[Reading Tips: 1V1, both protagonists are pure, sweet story, the heroine is beautiful.]

Killed by a Sage Emperor and reborn as his 13 year old self, Nie Li was given a second chance at life. A second chance to change everything and save his loved ones and his beloved city. He shall once again battle with the Sage Emperor to avenge his death and those of his beloved . With the vast knowledge of hundred years of life he accumulated in his previous life, wielding the strongest demon spirits, he shall reach the pinnacle of Martial Arts.