The Seven Guardians of Light (7光の守護者 Shichi no Hikari no gādian?), also known as the Seven Lights, are a small group of Keyblade wielders who are destined to oppose the Thirteen Darknesses and create the χ-blade in the process.
Kingdom Hearts 3D: Dream Drop Distance
Master Xehanort revealed that he knew his attempts to create χ-blade through the reunion of Ventus and Vanitas was a hasty attempt due to his impatience and that he had always been searching for a true way to forge it. For this reason he enticed Maleficent into capturing the Princesses of Heart, with his Heartless Ansem overseeing her progress, while his Nobody Xemnas created Organization XIII so his splintered selves could obtain the Lights and Darknesses, respectively. But, as Ansem failed to possess Riku and Roxas returned to Sora, Xehanort's new organization would be one member short so he decided to use Sora.
As Xehanort explained his plan to Mickey, in order to make sure the Seven Lights formed, Mickey hypothesizes that the current candidates for this role would be himself, Sora, Riku, Terra, Ventus, Aqua, and another he didn't mention out loud as he realized who the Thirteen Darknesses were. Xehanort explains that while the King was right, Terra was unavailable as he was his vessel and Sora was about to become the Thirteenth member of his Organization. This attempt, too, failed thanks to Lea, Donald, and Goofy.
As the Thirteen Darknesses return back to their timelines while short one member, Xehanort tells his opponents that the battle between his Darknesses against their Lights will happen and they will meet again at the fated place. Because of this threat, fearing Xehanort would go after the Princesses of Heart if they did not go through with it, Yen Sid and Mickey resolved to gather the Seven Lights. After Riku awakens Sora and Yen Sid grants Riku the title of Master, it is revealed that Lea can also wield the Keyblade, making him another potential member.
Kingdom Hearts III
Afterwards, Yen Sid sent both Lea and Kairi to Merlin, where the two were trained in order to join the Guardians of Light and be able to battle against the Thirteen Seekers of Darkness in equal footing. As this occurred, both Riku and Mickey sought out a way to rescue Aqua from the Realm of Darkness, while Sora began to travel the worlds in order to regain his lost strength. In time, he joined Riku and Mickey as the former battled against a corrupted Aqua, and succeeded both in expunging the dark influence from Aqua, and in rescuing her from the dark realm.
- Sora - A boy from Destiny Islands. His heart became connected with Ventus' before he was born and four years later it became a refuge for his heart as healed after his battle with Vanitas, thus playing a part in bequeathing the power of the Keyblade to Sora.
- Riku - A boy from Destiny Islands and childhood friend of Sora who was bequeathed the power of the Keyblade by Terra. His heart fell to Darkness before he could get his intended Keyblade, and was later possessed by Ansem, Seeker of Darkness. He has been on a journey of redemption ever since and has developed a resistance to the Darkness. As a Guardian of Light he was also aided by Riku Replica, whose heart he was sheltering.
- King Mickey - The King of Disney Castle. Mickey became a Keblade Master after being trained by Yen Sid, a former Keyblade Master.
- Aqua - A Keyblade Master trained in the Land of Departure. She was trained along side her friends Terra and Ventus by Master Eraqus.
- Ventus - A Keyblade wielder trained in the Land of Departure. He was the former apprentice of Master Xehanort, but he was used in an attempt to summon the χ-blade.
- Keyblade: Wayward Wind
- Kairi - One of the Princesses of Heart from Radiant Garden, but currently lives on Destiny Islands with Sora and Riku. She was accidentally bequeathed the power of the Keyblade by Aqua.
- Keyblade: Destiny's Embrace.
- Lea - A man from Radiant Garden and the true persona of Axel, a rogue member of Organization XIII and the best friend of Roxas and Xion.
- Terra - A Keyblade wielder trained in the Land of Departure. His body was possessed by the heart of Master Xehanort, but upon regaining control over his body, he joined the Guardians of Light, taking Kairi's spot from Xion.
- Roxas - The Nobody of Sora. Thanks to the research of Ansem the Wise and a replica created by Vexen that was able to contain his heart and memories, Roxas became real again and joined the Guardians of Light, taking Lea's spot.
- Xion - An experimental replica created by the first Organization. She was brought back by Master Xehanort to fill a spot in his Organization, but when her memories returned she chose to become a Guardian of Light, temporarily taking Kairi's spot.