Feitan stomps.

He has an ability that can cause mass destruction and basically summons the sun.

When he used it on Zazan was so powerful that all of the of the Phantom troupe had to evacuate by a mile radius.

Feitan is such a unique character because he only gets stronger as he gets angrier which is the opposite of conventional characters in fantasy. Hisoka pissing him off and playing games with him will only make the situation worse and he can't defend himself against the Pain Packer Sun no matter what he does with Bungee Gum.

Furthermore, Feitan is always shown to be very calm and collective as he is a torturer himself. This means that Hisoka can only make him angry but not even put him off psychologically.

When Hisoka hunts down the Troupe, Feitan will definitely be his biggest challenge as he hasn't fought him before like Chrollo so I personally think that overall, Feitan wins.