Alluka Zoldyck

Alluka Zoldyck is the second youngest child of the Zoldyck Family. Alluka is said to be a dark, uncontrollable child with the ability to grant wishes but can also cause large numbers of brutal deaths. Because of this vastly abnormal ability, Alluka has been locked up in a vault, behind four 10-digit-keypad password-protected security doors at home. (Source: Hunter x Hunter Wikia)