What To Do if You’re the Villain and the Heroine Likes Youu

‘Girl, I Just Want to Cultivate’ is a famous novel with multiple female heroine that expressed their interest in romance to the main protagonist, but the author of this book guarantees that this book is a single heroine story and not a harem story. But the Readers (including me) have expressed their doubts.
It wasn’t until I transmigrated into the story as the handsome antagonist that I realized the main character’s younger sister is the hidden final boss—a martial arts prodigy with an incredibly strong Yandere tendencies! And now, she has caught me. How can I make the female lead fall for the villain?