Xemnas, Saix, Xigbar, Xaldin, Marluxia, Larxene, Axel, Lexeaus, Zexion, Vexen, Luxord, Demyx, Roxas, and Xion, but she only appears in KH: 358/2
The members of Organization XIII are:XemnasXigbarXaldinVexenLexaeusZexionSaïxAxelDemyxLuxordMarluxiaLarxeneRoxasXion~By MapleLeaf~
The human forms of Organization XIII's members appear in Kingdom Hearts: Birth by Sleep for the PSP.
Organization XIII's members definitely existed at this point, but the name 'Organization XIII' probably wasn't created until the time of Kingdom Hearts Chain of Memories when Roxas joined, making thirteen members altogether. We know, because of the events in Kingdom Hearts Birth by Sleep, that the members of the organization were mobilized, but "Organization XIII" in specific might not have been established.
Zexion has no meaning in the Japanese language as it's origin is entirely English.The understanding behind the Organization XIII nobody names is that they are scrambled forms of their original (non-nobody) names, with the addition of X.Spoilers:As such, "Roxas" is just "Sora" with an X added. Similarly, "Zexion" is actually "Ienzo" with an added X.This applies to all Organization XIII members save for Xion, who is neither a nobody or Organization XIII member.
I believe it would be Xion, but if your going by the 13 organization members, it would be Roxas.
they hav no age they are immortal Roxas and Xion are 15
All of them.
maybe i dont know yet never tried yet
No because you haven't fought any members of Organization XIII in Kingdom Hearts 1, you haven't even seen a Nobody yet. In Kingdm Hearts 1 all of your enemies are either human or Heartless.
King Mickey and Riku wears Organization clothes because so the Organization XIII think that there members of there Organization XIII and DiZ gives them Organization clothes to help them on there journey on the ending of Kingdom Hearts RE:Chian in Riku's Story Mode.
Organization XIII got its name because it contains thirteen members. Although Xion is known as No. XIV (14), she is not a Nobody; she is a clone that was created from Sora's leaked memories during the events of Kingdom Hearts: Chain of Memories. Xemnas and Saix never considered her a real Organization member. She is more of a puppet meant to absorb the Keyblade's power.-Hope this clears up all of the confusion!-RoxasDive
nothing is actually mentioned about their height but i know Axel is the tallest and Xions the smallest