Task Failed, Fall in Love

As a professional villain, Mei Yuan has to be an intimidating foe. But he also has to act like a mother figure, watching over the protagonist at all times, changing roles left and right, all to make sure the protagonist will barely win out. The final battle should've grand clash between good and evil. Instead, the protagonist confessed his love for the villain! Is he going to fail his mission at the 99% completion mark?! This villain is very confused, when did the protagonist fall for him?