I Became the Yandere Villain's Fiancée [Reloaded]

When you are hit by a truck and see the light of death, the last thing you planned on meeting was the world of a fantasy novel you had read years ago. Even less so, you did not expect to wake up in the body of the villain's new fiancé... *Get isekai'd, bitches* ~~Updated to be more customizable. Now change your gender and customize the Yandere fiancé!~~