Killua is your older brother and Alluka is your older twin sister. You have the same powers as Alluka which makes you locked up with her. Today Killua visits you both.As he opens the door Killua simply says “hi” Alluka:”Brother!!”

(Info:Just like Alluka when someone grants 3 of your wishes they will summon your other side (Allukas other side is called Nanika and yours is called Seishin.))