I Signed In for a Hundred Thousand Years, Then My Junior Sister Dug Me Up

[Ding! Sign-in completed after one hundred thousand years. System fully loaded! Host Su Chen, awakening now!] When the cold mechanical voice exploded in his mind, Su Chen felt the eyelids that had rusted enough to serve as the foundation for the Demon-Suppressing Pagoda finally twitch. Deep in the earth's ley lines, in the bronze cage at the very bottom of the Qingyun Sect's Demon-Suppressing Pagoda, the green patina on the coppery skin of his “antique body,” which had lain there for a hundred thousand years, was flaking off like rain. “Awake? Finally awake...” Su Chen tried to move a finger with his mind and nearly snapped his rusted knuckles. “I've been signing in for a hundred thousand years. System, did you take me for a shared bike and leave me here to rack up a deposit?” A hundred thousand years ago, Su Chen had been the Qingyun Sect's greatest cultivation genius in a century. All because he'd had too much to drink, he somehow bound himself to this [Lie Flat for One Hundred Thousand Years Sign-In System]. Then the lousy System “invited” him into the bottom of the Demon-Suppressing Pagoda, claiming he could “build up his foundations, collect sign-in rewards, and amaze the cultivation world in a hundred thousand years.” And what happened?