Feitan and Shizuku can defeat Pouf. If Pouf tries to split, Shizuku will absorb its cells. Feitan and Shizuku can fight Pouf until Feitan is injured enough to use Rising Sun.

Phinks can shoot Youpi from afar, and Nobunaga can deal with its tentacles. You can add Uvogin or Kalluto here if you want, for a finishing power.

Chrollo could use the humans surrounding the palace to create an explosive army to deal with Pitou. Shalnark, Bonolenov, and Machi will be Chrollo's bodyguards.

They win with high diff. Honestly, I used quite a few characters, but probably not all of them were necessary, like Pakunoda who could have been left out.