The central twist of the film is the true identity of the Masked Man. He initially claims to be the Six-Eared Macaque, a known antagonist and impostor of the Monkey King in mythology. However, late in the film, he reveals himself to be the real Sun Wukong (the Monkey King), who has been living in disillusionment in Donghai. This reveal re-contextualizes his actions, shifting him from a shady informant to a legendary hero acting as a reluctant mentor.
Another key revelation concerns Nezha's past. Yunxiang learns that the original Nezha, after killing Ao Bing, arrogantly refused to apologize to the Dragon King, which led to him committing suicide to save his city from the Dragon King's wrath. This complicates the black-and-white view of Nezha as a simple hero, showing him to be proud and destructive. This knowledge forces Yunxiang to decide that he must be better than his predecessor, fighting not out of divine arrogance but for the people he cares about.
The film's climax sees Yunxiang sacrifice himself to kill the transformed Ao Guang and stop the tsunami threatening to destroy Donghai. In a metaphysical space, he fully unifies with the primordial spirit of Nezha, who then resurrects him. This act signifies his complete acceptance of his dual identity, becoming a new, more complete hero. The ending and post-credits scenes establish that he has embraced his role and will, with the Monkey King's guidance, seek out the other celestial weapons, setting up a larger cinematic universe and future conflicts with other reincarnated gods.