Square Enix have announced that they have collaborated with Microsoft to bring a new weapon, a bow called Azrael, to be used with Serah. The DLC will launch four days after the launch of FFXIII-2 on 7 February 2012 and will set you back 80 MS Points.
The official press release:
This weapon is named after an angel who represents spirits and death. It is believed to possess the power to change the owner’s destiny, and your Chain Bonus is upgraded when equipped. Serah alone has the ability to wield this legendary weapon. The player can obtain this weapon from Chocolina merchants, from Episode 2 onwards in the main game for 80 Microsoft Points via Xbox Live Marketplace for Xbox 360. Only Serah has the ability to wield this legendary weapon.”
Source : Eurogamer