I Became the Villain in a Romance Novel

He transmigrated into a female-oriented romance novel as the second villain—with his sister as the first. Armed with knowledge of the plot, he schemes to ally with a powerful righteous hero who appears later. But when the hero confronts him with a dangerous question—"Are you helping her or me!?"—he realizes he's become the ultimate villain. Meanwhile, the heroine demands to know when he fell for her, and his flowery confessions only dig him deeper. In a world of political intrigue and romantic entanglements, can a self-aware villain rewrite his doomed fate?