I Spent 300 Years Signing In at the Imperial Mausoleum, and Now I'm Invincible

He transmigrates into the Tang imperial mausoleum and becomes its guardian. He awakens a sign-in System. From then on, Jiang Yuan lives in seclusion at the imperial mausoleum, signing in every day. “Sign in at the Tang imperial mausoleum to receive the reward: 【Supreme Art】.” “Sign in before the tomb of the founding emperor to receive the reward: 【Heaven-Opening Sword Art】.” “Sign in inside the Spirit-Gathering Formation to receive the reward: 【Son of Heaven's Qi-Reading Art】.” Jiang Yuan plans to wait until he reaches the peak of martial arts before venturing out. But then, one day, spiritual qi revives and ancient powerhouses return. At this critical moment, Jiang Yuan strikes with his sword. Invincible beneath the heavens, he shocks the world!