Agui Ssiaseul Kiwo Beoryeotda

Astraea, the strongest swordswoman in the world. One day, she realizes that she has reincarnated as a character inside a novel. And that role is the one who gets killed by the Evil God, the final boss... During a mountain hike, she saves a child from assailants, only to learn that this very child is destined to become the Evil God. "Well then, since it’s come to this, how about I raise him properly and reform him?" So she takes the child in and begins to raise him. But then... "Rea. Where are you going? Are you meeting that guy again?" The boy has grown into an obsessive man who follows her everywhere, watching her every move. Somehow... it feels like she raised him the wrong way. (Source: Kakaopage, translated)