I, the Sect's Holy Son, Have Checked In at the Forbidden Grounds for a Hundred Years!

After transmigrating into a fantasy world, he becomes a sealed Saint Child, imprisoned in the sect's forbidden grounds. Unexpectedly, this activates the sign-in System. “Ding! Congratulations, Host. Sign-in at the forbidden grounds successful. Reward: a thousand-year-old spirit pill.” “Ding! Congratulations, Host. Sign-in at the library successful. Reward: a Heaven-tier magical treasure.” “Ding! Congratulations, Host. Sign-in at the sect's dragon vein successful. Reward: a heaven-defying cultivation technique.”...

He keeps quietly signing in, day after day. Finally, one day, when the Supreme Sect faces imminent destruction, he draws his sword!