Real Organization XIII

The real Organization XIII (真のXIII機関), also known as the thirteen seekers of darkness (13人の闇の探求者), is a group consisting of thirteen different incarnations of Master Xehanort that debuts in Kingdom Hearts 3D: Dream Drop Distance. It was first mentioned by Yen Sid in Signs of What's Next when he claims that one Keyblade Master will not be enough to counter what is "not a single one of Xehanort".

History
The true purpose of the original Organization XIII led by Xemnas was for each of the Nobody members to host a fragment of Master Xehanort's heart, turning them into clones of Xehanort, but the members' unforeseen independence made this goal impossible to realize.

However, in anticipation of this failure, Master Xehanort had arranged for Young Xehanort to be sent by Ansem, Seeker of Darkness to travel to different periods of time and gather different incarnations of Xehanort, who would be added to the ranks of a new Organization. Young Xehanort succeeds in filling twelve of the Organization's seats, and he and the revived Master Xehanort attempt to make Sora into the final vessel. When Sora is rescued by Riku, Mickey, and company, the Organization disperses to their proper times, while Master Xehanort remains confident that in time he will complete his Organization.

Main members

 * Master Xehanort: The original Xehanort and the mastermind behind all of his incarnations' actions.
 * Young Xehanort: Master Xehanort in his youth, who traveled through time with the assistance of Ansem; acts through a replica body in the present.
 * Terra-Xehanort: A version of Master Xehanort from when he possessed Terra; acts through Terra's recompleted body in the present.
 * Ansem, Seeker of Darkness: Terra-Xehanort's Heartless; acts through a replica body in the present.
 * Xemnas: Terra-Xehanort's Nobody and the leader of the first Organization XIII; acts through a replica body in the present.
 * Vanitas: The embodiment of Ventus's darkness who seeks to extract Ventus's heart from Sora.
 * Xigbar: Braig's Nobody and a member of the first Organization XIII, and actually Luxu in disguise.
 * Saïx: Isa's Nobody and a member of the first Organization XIII.
 * Luxord: A member of the first Organization.
 * Marluxia: A member of the first Organization XIII who sought to overthrow Xemnas.
 * Larxene: A member of the first Organization XIII who worked alongside Marluxia to overthrow Xemnas.
 * Dark Riku: Riku Replica's time-traveling heart within a new replica body.
 * Xion: Originally an unofficial member of the first Organization; acts through a replica body in the present.

Reserve members

 * Vexen: A member of the first Organization. Brought back only as a reserve member, mainly to continue the Replica Program.
 * Demyx: A member of the first Organization. His place was taken by one of the Replicas.

Other members

 * Replica Xehanorts: Replicas of Xehanort who assist him in Scala ad Caelum.

Echte Organisation XIII