System in Hand, I Rule the Three Realms tells the story of Ye Bufan, a young man from the human realm who unexpectedly obtains a mysterious System after his family suffers a calamity, setting him on the path to a comeback. Using the System's sign-in and quest functions, he quickly grows stronger. After getting his revenge, he is drawn into the conflict between the Immortal Realm and the Demon Realm. Along the way, Ye Bufan meets like-minded companions, including Huang Taotao of the Immortal Realm and Gu Jijiji of the Demon Realm. Together, they fight the dark forces seeking to shatter the balance of the Three Realms and vie for the "Heart of Chaos," which can change the order of the Three Realms. They successfully seal it away. But the crisis is far from over: an ancient evil sect now plots to awaken the sealed Demon God. Can Ye Bufan and the others turn the tide once more and protect peace in the Three Realms? See how Ye Bufan, with the System's help, makes his way across the Three Realms and writes his own legend!
