In the second season of "What's Wrong with My Big Brother," Dongfang Xianyun finds himself in a cultivation realm after transmigrating, only to realize he does not match the typical hero archetype. Convinced that his younger brother Yin Feixing—who has been reborn for revenge—is the actual protagonist, Dongfang Xianyun tries to stay close to this supposed hero to guarantee his own safety. Yet he is thrown off a cliff by who he believed to be his mentor, setting him on a dark path as a demonic cultivator. He is joined by the naive Mahayana-stage demonic cultivator Yi Xiangfeng, the flirtatious Dongfang Wuqiong, the anonymous top disciple of the Xuanming Sect, and Bu Suantian, another transmigrator who serves as the Heavenly Dao Messenger. As the Demon Subduing Assembly approaches, the conflict between righteous and demonic cultivators intensifies. Dongfang Xianyun, formerly the leading disciple of the Xiaoyao Sect and now a prominent demonic cultivator in the Bai Mei Sect, faces a critical life-or-death situation.