Board Thread:Questions and Answers/@comment-26005711-20151226104253/@comment-9051002-20170821025951

1v1 Hisoka but what I love about HxH is that Nen can change depending on your mental condition and no fight is certain.

I'm pretty sure that even tough Hisoka is stronger, enraged Illumi (When he threatened Killua) could've killed him. Just like enraged Gon could even take on Pitou.

Also note that Illumi is an assassin and is trained to kill you when you least expect it. So having him as an enemy would almost 100% guarantee your death