Okay, IU have recently been playing through all of the KH games, and one thing I noticed was Organization XIII, if you look carefully enough, each member has their actual body's name just added with an X, for example.

Roxas = Sora
Axel = Lea

These are the only two I have figured out, if you can name the other members, please do so.

Demyx = Myde.
Lexaeus = Aeleus
Xigbar = Braig
Vexen = Even
Xaldin = Dilan
Xemnas = Ansem

They're from the journal, if you look closely.

Anagrams, actually.

Sweet, thanks Nosoup.

No problem. And:
Saix: Isa

Zexion = Enzio i think

I noticed that as soon as I heard roxas. Then I discovered other org. XIII members followed the patern. But Xemnas sounds lame compared to Ansem or Xehanort. Xemnas sounds all lame and stuff.

Xemnas: Ansem
Xigbar: Braig
Xaldin: Dilan
Vexen: Even
Lexaues: Aeleus
Zexion: Enzio
Axel: Lea
Saix: Isa
Demyx: Myde
Luxord: Rould (not confirmed)
Marluxia: ?
Larxene: Larene or Lerane probably
Roxas: Sora (duh)