>>535906290
Either in some way and not visible, or the gene splicing modifications the AH project designed made them breathe in some way we can't know of, which wouldn't be too far fetched given their advanced technology even back then. Skadi and Laurentina have no gills/scales we can see, Gladiia had started to show scales on her neck (and more if you go by her 2nd skin), and Ulpianus covers himself up completely but it's been said his mutation is by far the worst so he could very well have visible ones underneath.