Jax's character arc is a Kaamatan passion play.
Jax's character is a perfectly self-contained Bambarayon-esque story, especially with regards to how both characters ultimately are sacrificial hinges for their respective narratives but still loom over them afterwards, one way or another. Being Dusun myself, realizing the parallels was very fascinating.
Despite this, Jax's arc does not put the feminine on the pedestal but leaves femininity in a neutral state and attempts to criticize tropes considered masculine instead.
For the sake of consistency, the male and female creator deities will be respectively called Kinorohingan and Suminundu, while their son and daughter Ponompulan and Ponompuhan, respectively. I also will refer to Jax with she/her pronouns.
One shared aspect is how the masculine rebels and retaliates out of greed and selfishness, with the unjust martyrdom of the feminine being the resolution of the conflict, just like how Ponompulan rebelled against his father Kinorohingan with humans on his side, followed by Kinorohingan unleashing the Great Famine upon humans in raging revenge disguised as justice, leading to Ponompuhan's (Ponompulan's sister) iconic sacrifice and the grieving of her mother Suminundu. Similarly, Jax's Ponompulan-like rebellion against her identity out of fear of truth causes her to sacrifice her transfemininity (Ponompuhan), snowballing herself towards abstraction.
Additionally, to balance out the selfishness of the masculine, the feminine is forced to be a symbol that fosters cohesiveness within the community. Ponompuhan's body parts become the various staple crops of the Kadazandusun today, and her soul becomes Bambarayon (spirit of the rice), whom humans lay out offerings to every year during Kaamatan (Sabah's Harvest Festival), led by bobolian (priestesses). Likewise, the abstraction of Jax serves as a constant collective reminder among the Circus cast of the danger of self-repression and distracting one's internal struggles with a facade of trickery, with Pomni harboring all of Jax's memories, including the idea of her transfemininity (Bambarayon).
Reading Jax's character arc as a retelling of Bambarayon's legend is a way to understand the latter from a fresh perspective, providing an apparatus to shift the main question from "why did Ponompuhan have to die?" to "why do the male deities act and react so violently in the narrative?". The moral burden of the legend is lifted from Ponompuhan as a symbol of women's quiet sacrifice in society, instead now laying on Ponompulan and Kinorohingan, and cisnormative masculine rage.
Ultimately, however, looking through the lenses of both stories at the microcosmic level provides a very good reminder about transfemininity, that it should not be buried or refused, and instead be embraced, despite the ego wishing to endure subsistence. Denial will not lead to cessation, only a famine of the self.