Eighty Years of Sign-Ins in the Inner Palace, and I Become a Martial Dao Sage

Ye Cheng transmigrates into the body of a eunuch who sweeps the floors, and wants only to keep his head down in the Imperial Library until he becomes invincible. Thanks to a sign-in System, he grows a little stronger every day. Several emperors of the Great Qian dynasty come and go without ever discovering this elder. Only when the barbarian army bears down on the border and the dynasty teeters on the brink of disaster does Ye Cheng leave the Imperial Library, cutting down a million soldiers with a single sword!