The guardians of light are a group of seven Keyblade Wielders gathered by Yen Sid to fight against Master Xehanort's True Organisation XIII.
The concept is actually brought up by Master Xehanort to Mickey. As the thirteen members of the True Organisation represent the thirteen darknesses that broke away from the Xblade, so the guardians of light would represent the seven lights that made up the other half. In reality, those seven lights created the seven Princesses of Heart. Xehanort therefore expects that, to avoid the Princesses being targeted, or to protect them after they are targeted, Mickey would create a team of seven guardians to replace them.
The official list of guardians of light has not yet been revealed and will presumably be finalised by the end of Kingdom Hearts III, in-game. Dream Drop Distance offers a potential line-up over its climax and secret ending. When Mickey is faced with the concept of the seven guardians he immediately lists off himself, Riku, Sora, Terra, Aqua and Ventus. In the secret ending, Riku brings Kairi to the Mysterious Tower; the title of the scene is 'Another Guardian of Light'. However, with Lea now possessing a Keyblade, the possibility of Roxas and Xion being recovered, and Terra's location unknown, that initial listing has the potential to change. DoubleCross (talk) 07:08, June 22, 2013 (UTC)