Board Thread:Questions and Answers/@comment-26005711-20151226104253/@comment-30523901-20170612075815

When it's fights based on super powers like this you have to look at the special abilities that they have. HIsoka has much simpler powers which means they are more easily deployed but at the same time his bungee gum is extremely versitile, allowing him to do everything from perform ranged attacks to enhancing his movement to stopping projectiles just to name a few. On the other hand Illumi needs the needles he carrys in order for his ability to work (which is a drawback), his powers are mostly for disguise and controlling puppets (which are far less useful and versitile in combat), and it's only real combat use is throwing the needles as projectiles (which Hisoka can block or dodge with his powers) or attacking with the needle men.

TLDR; It comes down to whether or not Illumi can find a large enough group of victims to use as sacrificial pawns. If he can then he distracts Hisoka long enough with small frys that he can use zetsu to land a sneak attack. If he can't find any pawns then his powers are useless and this come down to relatively normal martial arts skill vs superpowered martial arts skill AKA Hisoka wins