he is the other side of sora's heart. instead of giving my reasonings, i am just going to give proof.
unknown: you look like him
unknown: which means you are incomplete
http://sd.cubicnetwork.net/images/Sora/Twilight Town/60.png
http://sd.cubicnetwork.net/images/Sora/Twilight Town/61.png
just thoses clues proves that bhk is teh other side of sora's heart. how taht happen is unknown. some say it is when sora became a heartless when his heart split.
unknown: you look like him
unknown: which means you are incomplete
http://sd.cubicnetwork.net/images/Sora/Twilight Town/60.png
http://sd.cubicnetwork.net/images/Sora/Twilight Town/61.png
just thoses clues proves that bhk is teh other side of sora's heart. how taht happen is unknown. some say it is when sora became a heartless when his heart split.