Task Failed, Fall In Love

as a professional villain, mei yuan has to become an outstanding foe. but being the representative of male caretakers, he has to watch over the main character at all times, switching aliases left and right, making sure that the protagonist can rise to the top.at the final battle scene, it should've been be a grand clash between good and evil. instead, the main character confesses his feelings for the villain! working all the way to 99% completion but then the mission fails! the villain is very confused, when did the main character fall for him?