Abengane

Background
Abengane is an Exorcist ; one with the ability to remove Nen curses on himself or on other users. As one of the players hired by Battera to complete the Greed Island game, Hisoka finds Abengane on the island and hires him to remove the curse placed on Chrollo by Kurapika. One of the conditions for his ability to remove curses is that the creature he summons would attach onto himself, and devour both the Nen causing the curse and his own, rendering him unable to use Nen. The only way to rid himself of the creature is to fulfill the original condition for removing the curse.