The Obsessive Male Lead Wants To Become My Husband

I reincarnated as the wicked older half-sister of the female lead of a rated-19 novel.
And here, I’m destined to die at the hands of the obsessive male lead.
So, I desperately tried to prevent my sister and him from meeting each other…

“Sisterhood is a wonderful thing.”

Like a beast, the golden yellow eyes shone dangerously in the dark.

“But Evelyn, it’s time for you to know.”
“Cas, Duke Cassius…”
“I wanted only you from the beginning.”

How did I end up in this situation?