I Became the Younger Sister of a Regretful Obsessive Male Lead

One day, I transmigrated to an unknown story! My parents here have passed away, and it was only after being adopted by a new duke that I realized what story I transmigrated to… A tragic BL webtoon where all the characters die- and at the center of it, I’m the first side character to die! And on top of that, I’m destined to die by my favorite character, Lucian’s, hands?! Fortunately, or unfortunately, we’re here before the start of the tragedy. Since I’ve been adopted by the dukedom where my favorite character is, there’s still plenty of time to change the ending! However… I just wanted to change Lucian into a sweet guy and have a happily ever after, but why is his obsession coming towards my direction?!