The Heroine is My Stepsister, and I'm her Final Boss

Arnold never thought his gaming skills would land him in a romance novel—as a doomed side character, no less. To survive, he hijacks the heroine's “system,” bending the story to his will. But when he dodges a deadly duel, he catches the eye of the heroine, Lara, his own step sister—and her love is a dangerous game. Arnold must outwit the plot and his step sister who's not afraid to kill for love. In this LitRPG romance gone wrong, survival isn't just about beating the system—it's about escaping the heart of a yandere.