Namjuui Teuraumareul Chiryohaejueonneunde

When the reader wakes up in a novel as Liliope, a guide who tragically dies because of the unstable male lead, Octaeon, she has her work cut out for her. Liliope's death traumatizes Octaeon in the original novel, but the female lead helps him recover, and the two fall in love. However, Liliope’s brother, Hyacin, despises Octaeon for killing her and morphs into the novel’s villain. Refusing to let her death drag him into darkness and despair, Liliope decides to rewrite her ending. However, as she weaves her new fate, she realizes her ending isn’t the only thing that's changing.

(Source: Tappytoon)