Xion

Xion is the fourteenth member of Organization XIII, and is to appear in the upcoming game Kingdom Hearts 358/2 Days. At the Square-Enix press conference DK∑3713, she was revealed in a trailer to have strange connections to both Naminé and Kairi. A recent Famitsu article has stated that she has a "tragic but yet, brave fate." Xion has been shown in pain being held in Riku's arms, questioning her existence, indicating that her fate may indeed be tragic. Axel is quoted saying that no matter how often Xion tries to escape, he will always bring her back. This suggests that Xion is not in the Organization on her own will, but is forcibly kept a member of the Organization.

She appears to be good friends with Axel and Roxas, and they are often seen hanging out together in Destiny Islands. She seems to be rather kind, aiding Axel and Roxas in one mission and talking respectfully to Riku at Destiny Islands. She mentions to Riku she has an important friend, and asks about "that girl who was with Sora", referring to Kairi. Riku tells Xion she "must return to her true self", but she seems reluctant to do so as she now has friends. Roxas and Axel both confront Xion in Twilight Town, where she raises her Keyblade to fend off Roxas when he approaches her. When Axel meets her in front of the Twilight Town mansion, she orders him not to go easy on her, and Axel reluctantly summons his chakram and attacks. She seems to have been asleep for a while and was accidentally awoken. 

Special Abilities
At the Square-Enix press conference DK∑3713, she was revealed in a trailer to wield the Kingdom Key. Although she wields a Keyblade in release trailers, it is unknown if hers is a real Keyblade, as Riku claims Xion's is a fake, which seems possible as she did not summon her keyblade back when it was knocked out of her hand. Her Keyblade from the trailer has been revealed to be the Kingdom Key with a keychain, Sora's original Keyblade. Naminé also makes a reference to her while talking to DiZ, talking about connecting memories. She mentions that if memories begin to "leak" while being connected, and if those memories are connected to other memories, then those "leaked" memories cannot be restored. Naminé then asks if she (Xion) could endure such a thing. There is still no confirmation on her powers or abilities, although she's revealed to look and sound like Kairi and have black hair and blue eyes. Their physical resemblance is something Xion herself acknowledges, so it is not just coincidence.

Trivia

 * Xion is said to have ties between both Kairi and Naminé, suggesting that there is a relation between the three of them.