No Xemnas is the unknown.
These are the people in his group
#1 Xemnas "The Superior"
Leader and founder of the Organization XIII.
His true form was Xehanort, understudy of Ansem. Xehanort acts as the world's heart, its cry of battle. His research throughout his journey helped him achieve his leader name. When Xehanort became Heartless, and took on the name Ansem his Nobody, Xemnas, was formed.
Xenmas sought to take advantage of Sora to take care of the Heartless which opposed them to put the heart 'back'
#2 Xigbar
Xigbar has a strong will to fight, and has no emotions during battle. Even though he isn't the smartest, he can survive through instinct. His attacks are materialized by light.
#3 Xaldin
Xaldin uses lances as his weapon of choice. He arrives at Beast's Castle, and he is working with Beast for some unknown purpose. He uses the power of wind as his attacks, and he controls it with his 6 lances.
#4 Vexen - Deceased
Vexen was a researcher of the heart and in KH:CoM created a replica of Riku using data gathered from fighting him. Later in the game, at Twilight Town he taunted Sora and informed Sora of the other side of his heart. For this, Marluxia ordered Axel to kill Vexen. If Vexen was not killed, it could of ruined Marluxia's plan to use Sora as a puppet so that he could gain control of the Organization.
#5 Lexaeus - Deceased
Lexaeus was known as the brute force of the Organization due to his huge size and strength. He wielded the element of "Earth" and used it against Riku in battle. According to the "D Report", similar to Marluxia, Lexaeus (with others) had the intention to use Riku as a puppet. Riku eventully killed him in battle.
#6 Zexion - Deceased
Zexion is known for not wanting to get into combat. But after the deaths of Vexen and Lexaues, he was forced into action to make a last attempt to gain control of Riku. He used his dark powers to pretend to be Sora, but at this point Riku mastered the darkness and seen through the guise. After this point, he encountered Axel who now had the Riku replica by his side, Axel ordered the Riku replica to kill Zexion.
#7 Saix
Saix appears at the infamous Battle Scene, and uses a colossal sword as his weapon. He is a silent and powerful foe who will show no mercy. He himself is unknown, and his purpose is clouded in mystery. Does he know the whereabouts of Riku?
#8 Axel
Axel and the leader of the XIII Order are not particularly good friends, the reason for this is unknown. Whatever assignment he is given, it doesn?t matter to him whatever the mission is, he will complete it regardless. He says he has something in common with Sora, what could this possibly be? He uses the power of fire, and uses his Chakrams as mediums to fight.
#9 Demyx
Demyx uses a sitar as his weapon. The other members of the Order would say that he is somewhat childish. But in exchange to that, he is a strong fighter. He uses the power of Water to fight, and channels it through the Sitar.
#10 Luxord
Luxord uses cards as his weapon of choice. He is considered more of a strategist more than a fighter; he also has some traits as a Gambler. He thinks of his strategies as games, and is a very good tactician. He also uses gambling as an implementation of his fighting.
#11 Marluxia - Deceased
The superior entrusted Castle Oblivion to Marluxia, despite his low rank in the Organization. But he had no intentions of doing what he was told and instead teamed up with Larxene to attempt to take control of the Organization.
He did this by trying to gain control of Sora and use him as a puppet. By using Namine, he ordered her to get rid of Sora's memories of Kairi and replace them with Namine. By doing this, Sora would become more & more obsessed of trying to save Namine, thus Marluxia could then use Sora's fear to make him do whatever he wants him to do. Ultimately with the betrail of Axel, and the strength of Sora, Marluxia's life came to an end.
#12 Larxene - Deceased
Larxene wielded the element of "Thunder" and fought several times in battle against Sora. She teamed up with Marluxia and later tried to also get Axel to help gain control of the Organization. In addition, she also taunted Sora to forget his memories of Kairi and become more & more obsessed with Namine. In the end, she was killed by Sora in battle.
#13 Roxas
Keyblade dark weilder. Added to Sora's form with him unaware at the time. This form he undertakes is only visible to Sora.
Killa Kev2.0 the Twilight warrior only bows down to the King of Games who legacy will live on forever.