Ba, the current chairman of the Beaten Hakka family, has five children, but only the fourth son is the most mysterious. No one knows whether he is a boy or a girl. I don't know anything about appearance, personality, gender, or name. Legend has it that he was a boy named Alluka. Legend has it that he and Killua, the third son with the best qualifications in the history of beating the enemy Hakka, are twins. Legend has it that since they are twin brothers, he and Killua look exactly the same. Legend has it that he was thrown into Meteor Street right after he was born. However, legends are always legends. No one knows whether these legends are true or false. He is always a mystery...