The trickster archetype is basically where a character could be disruptive, mischievous and humorous, all while adding onto the story. Usually with the trickster archetype, it comes from the feeling of wanting to get something out of sabotaging the story. This could possibly be a higher ranking, money, respect, etc. The trickster will go out of their way to negatively impact the flow of the story for their own selfish gain, not taking into consideration that their actions have consequences. Also, even in the circumstances they do know their actions are negatively affecting the story, they do not care and proceed without caution.
Mushu the Dragon embodies the trickster archetype throughout the entirety of Mulan. In the beginning, he lies to her about being a powerful dragon sent from her ancestors to guide her, when in reality it was a scheme to get his credibility back. He does multiple things throughout the story that negatively affect Mulan, and the track of the story itself. However, through all of this, he still manages to subvert the trickster archetype and prove to his audience that he has more depth than a "simple jokester". While still lying to Mulan, he begins to do small things that will help her succeed and guide the story in a different direction. He seems to go back and forth between sabotage and guidance, therefore truly throwing the audience for a loop. In the end, he comes up to the plate and decides to be a form of support for Mulan, rather than purposely drag her down. He ends up guiding her through the next movie as well embodying the archetype of mentor.
This writer chose to have Mushu subvert this archetype because the story needed a little bit of chaos. Mushu is a very humorous character that is loved by the audience, even though he is a partial villain. By adding his tidbits, he moves the story alone, both negative and positively. Then, when everyone is disappointed by his negative involvement, he recaptures his audience by being endearing and genuinely supportive towards Mulan. By proving that even through he had bad intentions, he still had a heart and did take into consideration Mulan’s role in the story, showing us immense character development. This writer found a way to add an interesting twist to the story while still allowing Mushu to be a lovable character in the end.
Cover credits to Identified as He Dazi (赫達資) - Selections. https://commons.wikimedia.org/w/index.php?curid=34822846