I Became the Younger Sister of a Regretful Obsessive Male Lead

I’ve transmigrated into the world of the BL webtoon <In The House of Dolls, There’s Another Doll Living There> where I left my one and only spiteful comment. On top of that, I become the adopted younger sister of my favorite character: the obsessive male lead who is later regretful for his actions, but still dies along with the duke in the end. So, I was determined. Since I have transmigrated into this world, I can’t stand by and watch my favorite character die. Additionally, I also don’t want to die. That’s why, author, I’ll need to change the tags and the ending of this webtoon slightly!