The Terminally Ill Villain Supports My Broken Engagement summary:

After dying in a car accident, I possessed the villainess 'Daphne' in an R-rated dark romance novel."Of all people, why did I have to possess her? This life isn't going to be easy either..."But this life is surprisingly sweet and enjoyable!Thanks to the knowledge of herbs I gained in my past life to make a living, I developed a hit business item."My sister is a hero who saved us!""Weren't you calling me a witch before?""Th-that was in the past...."I also gained adorable twin cousins.Somehow, I ended up restoring strained family relationships, making my taciturn and awkward family members cry tears of joy.And even..."Why would you eat something unsavory when there's something delicious right in front of you?"I even acquired a business partner who, despite being frail but full of charm, is determined to win me over with their good looks! (Of course, I didn't realize this innocent Grand Duke was the mastermind behind everything at the time.)Could life get any better? A 200% happiness index, living the high life as a villainess!