Transmigrating to the Tang Dynasty, I Became Li Shimin’s Brother-in-Law

I transmigrated to the end of the Sui dynasty and got stuck with a ridiculous dating app System. It can bind me to only one woman, and it insists on judging her by her social status to determine my points and rewards. I thought I was destined to die alone, but then fortune fell from the heavens. Li Xiuning, daughter of Li Yuan and sister of Li Shimin, was gravely ill and looked like a vengeful ghost! For the points, I’d go for her even if she looked like a vengeful ghost. Heck, I’d even go for a real ghost. I just never expected... this godawful taste in beauty would make me laugh myself silly!