Board Thread:Questions and Answers/@comment-25951143-20150101110046/@comment-26715302-20150823151201

" This inconsistency may be due to Killua's intimate and understanding bond with Alluka, hence he would know and care that Alluka identifies as female, versus Illumi and Milluki's cold and dehumanizing attitude toward Alluka."

HXH Wikia editors confirmed to have cold and dehumanizing attitudes.