Member 13 in the Organization, Roxas the Key Of Destiny
Roxas is Sora's Nobody (his name is an anagram of Sora with the letter X added.) and the newest, not to mention youngest member of Organization XIII, though while he was in the digital Twilight Town created by DiZ he was unaware of this for a long time. He was created in Kingdom Hearts after Sora battled Riku/ Xehanort's Heartless. (This was at the point when Sora thrust Riku's Keyblade into his own heart to release Kairi's, although this turned him into a Heartless. He was later changed back by Kairi herself. Roxas has no memory of being Sora but does begin to have dreams about him at the beginning of Kingdom Hearts II, when he is a playable character and Sora's memories are returning, thanks to Naminé.
In battle Roxas wields two Keyblades, the Oathkeeper and Oblivion. He controls the element of light and the Samurai Nobodies, possibly due to his acrobatic nature - fans will notice that when he duels with Sora he performs many more stunts than the other Members ever do or, possibly, are capable of (excluding, perhaps, Xemnas who is able to jump to the top of Memory's Skyscraper. However, Roxas and Sora are both able to run up its walls).