Captain’s gender (and appearance, for that matter) is intentionally kept hidden throughout the entire comic. They seem to self-identify (at times?) as a woman, and there are various clues that they were assigned female at birth, but other characters swap pronouns frequently, they themself never specify explicitly, and they are described as having a deep, booming voice (though it’s speculated to be a voice modulator).
But the best part is that Captain’s gender is literally incomprehensible. Here’s an excerpt from one of the panels:
"I looked at jubilant Captain and wondered whether the cubes would try to dissect h…. hi… he… What? Annoyingly enough, even being dead and out of synch with the universe didn’t allow me to mentally focus on Captain’s gender. There is definitely something wrong with Captain. Perhaps it is something awful that is not meant to be discovered? Or…? Damn it! The harder I tried to ponder on what exactly the Captain was, the more my mind burned with confusion. I felt a presence of unnatural apathy settling over me. I mentally fought against it and discovered a great sense of DOOM flooding into my head, telling me not to inquire further, lest the Universe fold in on itself.”
What better role model than a strange unknowable entity?
Anyway, besides that, the world building is rather nice and the art is absolutely flooring. In short, I highly recommend this comic.