This is just a theory=
I've noticed that all the order members have one "x" in their name=
1) ?
2) Xigbar
3) Xaldin
4) Vexen
5) Lexaeus
6) Zexion
7) Saix
8) Axel
9) Demyx
10) Luxord
11) Marluxia
12) Larxene
13) ?
BHK's name is Roxas. It has an "x". So, could it be that he is the superior or...