User blog comment:Martialmaniac/Alluka gender poll (not binding)/@comment-28556051-20160610043735

If Alluka didn't identify as any gender then gender-neutral makes sense, however Alluka's beloved Killua-niichan refers to Alluka as his little sister. He even immediately reinforced with Tsubone that Alluka is a girl right before they were leaving the Zoldyck Estate. I'm going to assume that Killua's so adamant about this because Alluka has told her beloved big brother that Alluka identifies as female. So I don't think it'd be wrong to assume Killua's got it right and take his example: Alluka is female.

Based on the rest of the Zoldycks Alluka was likely born male but later self-identified as female but no one except the big brother that loved Alluka paid attention to this.

Nanika seems like a separate entity to Alluka so may very well be anything. Can anyone confirm or deny what Nanika identifies as?