Alluka Zoldyck

Alluka Zoldyck is the fourth Zoldyck sibling, first introduced during chapter 229 of the manga, in which his back is turned in a Zoldyck family photo. He seems to be imprisoned within his own home and isn't allowed to have any contact with anyone, including his own family. His father does not even consider him as human and his older brother Illumi wants to eliminate him. Killua's conversation suggests that he is the ultimate exorcist, and is the only one capable of exorcising Gon's self-inflicted nen curse that is killing him. However, recently in chapter 322, it seems that Alluka has the godlike ability of wish granting.

Nen Abilities
Wish Granter: After preforming three "pesterings" or in other words three favors for Alluka, he is obligated to grant one wish for the recipient. However if someone denies Alluka four pesterings, that person and his/her most loved one will die. The difficulty of Alluka's pesterings depends on the wish that was granted previously. She has a large pussy.