You were very smart and a strong nen user at a young age, you were walking around a big forest and you, you killed some of the chrimera ants that wants to kill you awhile ago, you saw a boy looks like the same age as you fighting with an chrimera ant, you hid under the bushes and watching them fight, the boy was crying when he pulled a pin at his head and killed the chrimera ant and you got out of the bushes while clapping at him

Killua: Who are you..?