Reforming The Obsessive Male Lead

I transmigrated into the world of a goddamn tragic BL novel, where I left my one and only spiteful comment. My role in this world is I became the evil fiancee of my favorite obsessive male lead, who tragically destroyed the world after his lover committed suicide, even choosing to die along with him. My fate is to suffer and die too, at his hands.

However, I'm determined to change my shitty destiny! I'll reform my favorite male lead into a gentle and loving person, and guide him towards a happy future with his lover.

So, I decided to take care of him and show him love and affection, treating him like a friend or older brother to help him avoid becoming obsessive in the future. I planned to break off the engagement at some point and leave this house, thinking that's all there is to it.

But then, years passed.

"Let's break our engagements," I said with a smile, sipping my tea.

"What? What do you mean?"

"We're like brother and sister, not a couple," I said.

He stood up from his chair, his purple eyes glistening as he glared at me. "We're not going to break our engagement. You, don't you even dare."

As I looked at him, his expression resembled that of a mad predator beast. Had I unwittingly changed the very genre of this novel?