From the Start, I Tricked the Female Emperor, and Now I’m Invincible

[Fantasy, transmigrate, academy, high martial arts, one heroine, invincible, System, play the pig to eat the tiger] He has barely transmigrated when he discovers his cultivation has been crippled. Fortunately, his System awakens just in time. While the Empress is still a poor, helpless girl, he goes straight to work fooling her. With demonic beasts running rampant and the beastfolk invading, a mysterious figure single-handedly suppresses the beastfolk. When everyone asks who he is, the mysterious figure replies: “I'm just a cleaner at Xinghe Martial Arts Academy.” A year later, as the myriad races invade and humanity faces annihilation, their powerful warriors despair when they discover they can't even defeat a single student from Xinghe Martial Arts Academy.