Demon Revival: Inheriting the Old Celestial Master's Legacy from the Start

From the start, he transmigrated into a world where demons and monsters had returned, only to be attacked by a monster right away. He thought he was done for. But at the critical moment, he awakened a sign-in System.

"Ding! Congratulations, Host, you've successfully signed in."

"Ding! Congratulations, Host, you've obtained the inheritance of the Celestial Masters' Mansion."

"Ding! Congratulations, Host, you've inherited all of the Old Celestial Master's cultivation."

"..."