I Became Close to the Villain

A brief description of the light novel I Became Close to the Villain:
Vianne reincarnated into a book with memories of her previous life. She realizes that she was born as a child next door who was killed by the villain, Idris.
Approaching Idris to survive, she soon becomes indispensable to him.
But is it because they are too close? As the original story gets tangled little by little, Vianne faces another crisis.
In a moment of despair, Idris sacrifices himself to save her. So Vianne lets him go forever.
And ten years later. She, who thought he was dead, appears in front of Vianne.
“I want all of you, Vianne.”
He became the head of the villains!