Jax is shown in the pilot to be a smug, mean character, but that didn’t stop people from liking him, seeing his words as teasing more the bullying before episode two was release, but the tide started to shift more when said episode came out, with him acting more like a bully and causing problems on purpose with no seeming other reason than him wanting to. Of course, he still had fans, and anyone being upset kind of forgot about it mostly for the rest of the show as we slowly watch Jax push everyone away, up until the final, where Jax’s abstracts, where his body distorts in a jagged dark entity with eyes all over. But, while there was some complaints about how sudden it was, the main thing that changed and really split the fandom with their opinion of Jax, is when it was also heavily implied that Jax, is a trans women.
It's not outright implied that Jax is trans until ep 5, 6 and 8 of the show, where the gang is sent on multiple short adventures in the first ep mentiond. Durning the star watching one, Jax says to the main character, Pomni, that “My ears and tail are the pinnacle of Masculinity” After which Pomni comments that he doesn’t have a tail, then Jax looks around wondering where it went, and Pomni saying she never saw him with one. After that episode, Jax always has a tail, and is more closed off to her, which to me relates to someone getting pointed out that they don’t really act “like their gender” when they say they do and shutting them out after that so they don’t have to think about what that implies and look inwards. The next hint in ep 5 is during the bar adventure, after a few drinks, Jax makes an off hand comment to Zooble, a side main character who happened to be Nonbinary. The comment reads as an insult that a member of the queer community would say to another, like an inside joke. The last piece of evidence in this episode, is the maid dress scene. You see, though out the episode, the character where able to vote on things to do during the adventure, and the last one, was to poof Jax into a maid dress since he was being mean to everyone. He got very upset about this, more than just uncomfortable, which is why most people read it as him being force to confront how he’s feels about it. The is also a small hint in the second last episode, in the torment scene, where Caine, the AI ringleader of circus, goes full AM on the cast, with Jax’s scene being circled by shadows of two of his friends who have abstracted, Kafmo and Ribbit, as well as Pomni, laughing at him before pealing off his skin, refiling the yellow yolk like color of his body. The scene plus the scene where Jax and Pomni get into a fight in episode 6, where Jax says “I’m just a misunderstand little chicken feates in an egg” seems to be hinting at the saying of calling someone who is trans but hasn’t realizes or accepted it yet, an Egg. At the time, people were unsure if Jax was really trans, with it mostly being a fun headcanon that people would draw art for, which I do also think it’s why people didn’t really complain about it, since it was shown fully in the show, but all that was changed when the final came out. .
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