Board Thread:Questions and Answers/@comment-26005711-20151226104253/@comment-27503442-20151231121010

Maybe Hisoka wants to keep Illumi around because of his abilities (or something like that). I dont't thinks that's it because Hisoka was talking about killing Killua and making Illumi his enemy the the CE arc. Anyway, I think Hisoka would win. Illumi might be a little bit hesitant to fight Hisoka because of his assassin training (the whole "don't fight someone unless you are certain of victory" thing). I think Hisoka hasn't shown an interest in fighting Illumi because he knows he can win.