What is Chin-Kee's true identity at the end?

At the end of American Born Chinese, Chin-Kee is revealed to be the Monkey King. Chin-Kee, Danny's embarrassing Chinese cousin, accompanies Danny to school whenever Chin-Kee is in town visiting Danny and his family. He exhibits stereotype after Chinese stereotype, which Danny finds endlessly humiliating. Chin-Kee's name and behaviors are an interesting comment on the racist perceptions many Chinese people must endure; the name Chin-Kee echoes the pejorative "chink" or "chinky," which is a racist way of referring to Chinese people.
Chin-Kee turns into the Monkey King when he and Danny engage in a kung fu fight towards the end of the novel. The anger that Danny feels while fighting Chin-Kee is inspired by all the stereotypical behaviors Chin-Kee exhibits; Danny's rage towards Chin-Kee represents Danny's anger with racism in general. Only when Danny experiences this rage honestly is he able to confront his true Chinese self, Jin. In this way, the Monkey King as Chin-Kee helps Jin in a significant way, though at first Chin-Kee just seems like an embarrassing relative whose role is simply to annoy Danny and make him uncomfortable.