The leader (chrollo lucilfer) and founding members (feitan, machi, uvogin, nobunaga, franklin and pakunoda) of the troupe all came from meteor city.
Uvogin Hunter X Hunter Phantom Troupe / Uvogin was very powerful and he did kill a bunch of the shadow beasts (the strongest nen users in the world of mafia), but one of them did inflict a paralysing poison on him and it was confirmed that he could also secret a powerfully.