I've already become a god, and you're telling me about the ancient demon invasion?

Wang Tianlong had been cultivating diligently in the immortal cultivation world for a thousand years. Possessing a mysterious system, he was only one step away from the late-stage Nascent Soul realm and ascension. However, at this crucial moment, the world drastically changed, and ancient demons invaded—only then did he realize that he had transmigrated not to an ordinary immortal cultivation world, but to the turbulent ancient era of "A Record of a Mortal's Journey to Immortality." Amidst the smoke and fire, he glimpsed the legendary "Ice Soul Fairy" and caught a glimpse of the Silver Moon Wolf Queen traversing the battlefield. In the instant of his life-or-death struggle with the ancient demons, an unexpected spatial rift swallowed him. When he opened his eyes again, he was in the unfamiliar "Eastern Fence Realm." He discovered that his immortal cultivation world not only had Old Demon Han wielding a small green bottle to accelerate the growth of spiritual herbs, but also Wang Changsheng refining materials with a small cauldron. And looking at himself, the system that had repeatedly helped him overcome difficulties still displayed the same unspoken words on its panel: "One-Slash System, assisting fellow Daoist in ascending to immortality in broad daylight."