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The Thirteen Seekers of Darkness (13人の闇の探求者 Jūsannin no Yami no Tankyūsha?), also known as the Real Organization XIII (真のXIII機関 Shin no Jūsan Kikan?), is a group consisting of thirteen different incarnations of Master Xehanort that debuts in Kingdom Hearts 3D: Dream Drop Distance. The main goal of the group is to clash against the Seven Guardians of Light at the Keyblade Graveyard in order to forge the χ-blade, a weapon that would allow its user to open Kingdom Hearts. They serve as the main antagonists of Kingdom Hearts 3D: Dream Drop Distance and Kingdom Hearts III.
The actual purpose of the original Organization XIII was to host a fragment of Xehanort's heart in each member, turning them into his vessels, therefore replicating the thirteen pieces of darkness that emerged from the shattered χ-blade. However, many of the original members turned out to be either too weak or traitorous, leaving only Xigbar and Saïx as worthy members. However, Master Xehanort managed to gather 12 vessels of himself thanks to Young Xehanort and Ansem, Seeker of Darkness, though he failed to make Sora the last one, and fled with an incomplete Organization to put his plan in practice. Yen Sid has already told Mickey about this in Signs of What's Next, when he said that one Keyblade Master alone will not be enough to face what is "not a single Xehanort".
Xehanort, as Ansem, Seeker of Darkness, traveled back in time to visit Young Xehanort who was still living on the Destiny Islands, and gave him "instructions" about the great projects he had in store. Thanks to Ansem's power of Time Travel, Young Xehanort traveled through different future periods to his own, and made contact with the vessels of pure Darkness necessary to reform the Real Organization XIII.
Kingdom Hearts Birth by Sleep
Not being able to carry his own physical body through the ages, Young Xehanort had to use blank Replicas designed by Even to recruit his Seekers of Darkness. Arrived at the time of his future-self's first attempt to provoke the Second Keyblade War, Young Xehanort recruited Vanitas, whose heart of pure Darkness was deemed "incomplete" without Ventus's heart of pure Light. Meanwhile, in the Radiant Garden, Master Xehanort met Braig, a guard of Ansem the Wise. Together, they mounted a plot to make Terra succomb to Darkness, which caused Braig to lose his right eye. But to ensure the loyalty of his "new partner", Master Xehanort implanted a fragment of his heart in Braig, to make him a vessel.
Between Kingdom Hearts Birth by Sleep and Kingdom Hearts
When Master Xehanort's heart took possession of Terra's body, giving birth to Terra-Xehanort, Young Xehanort arrived to recruit him. But after a violent fight against Aqua at the Radiant Garden, during which the latter had to sink into the Dark World to save Terra, Terra-Xehanort became amnesiac, remembering only calling herself "Xehanort" when later Ansem the Wise discovered him. It was here that Ansem decided to recuit Xehanort as his apprentice, alongside Braig, Dilan, Even, Aeleus and Ienzo. But very quickly, Xehanort soon betrayed Ansem, even stealing his research and identity, and banishing him in the Dark World. Then, he decided to conduct many experiments on the hearts, bringing him and his other colleagues, including Lea and Isa, to divide into Heartless and Nobodies. During the process, Xehanort, became Xemnas, and made Isa, to become Saïx, one of his vessels.
When Ansem, Seeker of Darkness, caused Riku to succumb to Darkness to take possession of his body and recover all of his former powers, Young Xehanort arrived to recruit him.
It's hard to explain from when Young Xehanort recruited Xion to replace Vexen: she could very well have been recruited just before developing her own personality in contact with Roxas and Axel, or after having absorbed almost all the memories of Sora present in Roxas and her final brainwashing by Xemnas and Saïx.
After Vexen, Axel, Larxene and Marluxia used Naminé's memory manipulation powers to make Riku Replica believe he was the real Riku during the time Ansem, Seeker of Darkness, had taken possession of his body, the Young Xehanort recruited him as Dark Riku to replace Demyx.
Between Kingdom Hearts Birth by Sleep and Kingdom Hearts II Some time before Xemnas gets eliminated by Sora and Riku, Young Xehanort arrived to recruit him.
Xemnas and Ansem, Seeker of Darkness, having been eliminated, recompleted Master Xehanort and Terra in their original forms. Unfortunately however, Terra could not escape with the heart of Terra-Xehanort implanted in him, and was forced to remain as the Guardian that served Ansem and Terra-Xehanort. Young Xehanort later arrived at Ansem the Wise's laboratory in Radiant Garden, where were Braig, Dilan, Even, Aeleus, Ienzo, Isa, and Lea, were restored but still unconscious. Braig, the first of them to regain consciousness, was then informed of Xehanort's plans to reform Organization XIII, and he agreed to reinstate it alongside Isa. In the end, Braig and Isa returned themselves to their Nobodies forms as Xigbar and Saïx.
Shortly after they were recompleted, Lauriam, Elrena and the original beings of Luxord and Demyx were invited to become Nobodies again to join the Seekers of Darkness, which even Lauriam and Elrena accepted, despite their internal rebellion as Marluxia and Larxene.
During Sora and Riku's Mark of Mastery exam in the Sleeping Worlds, where the laws of Time Travel were more "flexible" than in the Realm of Light, Young Xehanort, with the aid of Xemnas, Ansem, Xigbar, Vanitas, and even Dark Riku, intervened to lure Sora to The World That Never Was and to make him their thirteenth vessel of pure Darkness. When Young Xehanort, with Xemnas and Xigbar, managed to knock Sora into his trap, the three of them took him to Where Nothing Gathers in the former Organization's fortress, and summoned Ansem, Saix, Vanitas, Larxene, Luxord, Marluxia, Demyx and Terra- Xehanort, to welcome to recompletion of Master Xehanort. As Master Xehanort prepared to make Sora his final vessel, however, Riku, joined by King Mickey, tries to stop him, but are stopped by the Young Xehanort, followed by Xemnas and Ansem. Lea arrived and successfully retrieved Sora's sleeping body, but was promptly countered by Saïx, much to Lea's shock. It wasn't until Donald and Goofy finally intervened that the twelve Seekers of Darkness ran out of time and had to return to their original timelines. However, Master Xehanort assured Mickey and the other Guardians that both the 13 Seekers of Darkness and the 7 Guardians of Light will meet at "fated place", the Keyblade Graveyard.
Despite being recompleted, Even approached Saïx to reprise his Nobody status as Vexen again and join the Seekers of Darkness. At first, he wanted to continue his Replica Program, and create Replicas real enough to exist as full-fledged beings, unlike previous models that were just as "fragile" as Nobodies. Thanks to Vexen's research, Xehanort obtained vessels that were strong enough to accommodate the hearts of Young Xehanort, Ansem, Xemnas, Vanitas, and even Dark Riku and Xion. With the integration of Dark Riku and Xion, Demyx and Vexen were "benched" as reserves members, allowing them to discretely sabotage Xehanort's plans, such as freeing Ansem the Wise and offering a Replica for the heart of Roxas.
- Master Xehanort - Original incarnation of Xehanort, a Keyblade Master who masterminded behind all the chaos and destruction that has besieged the Realm of Light thus far.
- Attribute: Darkness.
- Weapon: Keyblade (The Gazing Eye).
- Xemnas - Master Xehanort's Nobody. He founded the original Organization XIII, however Sora and Riku, as well as internal strife quickly reduced their numbers. Sora and Riku destroyed him, causing him to fade away into nothingness, however due to Young Xehanort's meddling in time he has returned.
- Ansem, Seeker of Darkness - Master Xehanort's Heartless. His missions were to both enable Xehanort's younger self to travel through time and oversee Maleficent gather the seven Princesses of Heart. Though he possessed Riku to regain physical form to go after Kingdom Hearts, Sora put an end to his plans. His Darkness lingered within Riku until the boy put an end to him, however he has been revived due to Young Xehanort's travels through time.
- Xigbar - Nobody of Braig, a mercenary hired by Master Xehanort to help speed Terra's descent into Darkness, Xigbar was the second member of the original Organization XIII, however Sora put an end to him. Despite this he has returned due to Young Xehanort's interference. He reveals that he joined Xehanort so he could claim the power of the Keyblade as his own, although it is revealed later that he had another reason.
- Vanitas - Embodiment of the darkness of Ventus' heart created by Master Xehanort. Due to Ventus being connected to Sora's heart, Vanitas is connected to Sora too.
- Terra-Xehanort - The body of Terra possessed by Xehanort's heart.
- Saïx - Nobody of Isa, and the seventh member of the old Organization XIII. His reasons for becoming a member of the True Organization XIII are because he believed that "Subject X", his friend from when they were human, Lea/Axel, had forgotten about him and grew jealous when he made other friends. Sora ended him once before, however due to Young Xehanort he has returned.
- Marluxia - Nobody of Lauriam and eleventh member of the old Organization who tried to take over it.
- Larxene - Nobody of Elrena and twelfth member of the old Organization who tried to take it over alongside Marluxia.
- Luxord - Tenth member of the old Organization. Original persona unknown.
- Dark Riku - Replica of Riku is used as one of the Seekers of Darkness.
- Attribute: Darkness.
- Weapon: Sword (Replica Soul Eater).
- Young Xehanort - Younger version of the original Xehanort. Meeting Ansem, Xehanort was enable to journey through time as an insurance plan in case he and Xemnas failed on their own. It is due to him that the True Organization XIII was able to rise.
- Attributes: Darkness and Time.
- Weapons: Unnamed Keyblade and unnamed Etheareal Blades.
- Xion - Fourteenth member of the old Organization, now used by Xehanort in order to fill up a spot in the new Organization XIII.
- Demyx - Ninth member of the old Organization.
- Replica Xehanorts - Dozens of Replicas created from the Thirteen Seekers of Darkness, except Master Xehanort.
- Attribute: Variable.
- Weapon: Variable.
By the end of Kingdom Hearts III, the Thirteen Seekers of Darkness were defunct, with some eliminated, some returning to their own time and some being re-completed into their original selves.
All members will be presented here in order of the end of their time as a chosen seeker of darkness:
- Vexen - Betray the Seekers of Darkness by rescuing Ansem the Wise from their clutches in Twilight Town.
- Demyx - Betrayed the Seekers of Darkness by delivering a blank Replica to Ienzo in the Radiant Garden to allow the resurrection of Roxas.
- Dark Riku - Dark Riku was defeated by Sora, Riku and Riku Replica, the final blow being carried by Riku Replica. It was discovered that Dark Riku was not the real Riku from the time when Ansem had taken possession of his body, but the Riku Replica from the time Naminé had reconstituted his memory so that he thinks he is the real Riku. With that, the heart of Dark Riku returned to its rightful place in the timeline, and his body went on to serve as a vessel for the heart of Naminé.
- Xigbar - Xigbar was defeated by Sora and Riku. It was later discovered that he merely simulated his elimination, technically making him one of the only survivors among the Seekers of Darkness, with Xion and Terra, to be able to recover the Gazing Eye, as well as the Black Box, and fulfill his role as Luxu. It is unknown if he returned to being Braig or if he has remained as Xigbar.
- Luxord - Luxord was eliminated by Sora. Before disappearing, he will give a "wild card" to Sora so that it "turns the tables". It is not yet known whether he was re-completed.
- Larxene - Larxene was eliminated by Sora and Mickey. She admitted that she had followed Marluxia in both Organizations XIII in order to repay her "debt" to him. It is not yet known whether she was re-completed to become Elrena again.
- Marluxia - Marluxia was eliminated by Sora and Mickey. Before disappearing, he thanks Sora for returning the memories of his old life. It is not yet known whether he was recompleted to become Lauriam again.
- Vanitas - Vanitas was defeated by Sora, Ventus and Aqua. Vanitas declared himself satisfied with the role he had plays as a shadow cast by the light of his "brothers". With that, the heart of Vanitas returned to its place and time of origin.
- Terra-Xehanort - Terra-Xehanort was temporarily neutralized by Sora, Ventus and Aqua before the defeat of Vanitas, then completely defeated by Sora and the Guardian, who turned out to be Terra's Heartless. With that, the heart of Terra-Xehanort was returned to its original time, and the real Terra reclaimed his body to become an additional Guardian of Light, technically making him one of the only survivors among the Seekers of Darkness, with Xion.
- Xion - As she was about to "finish" Lea on Xemnas' orders, Roxas will temporarily take possession of Sora's body to prevent her, and, by uttering her forgotten name, will return her all his old memories. Xion will then find again her place in the memories of her friends, especially Lea, and will become an additional Guardian of Light, technically making her one of the only survivors among the Seekers of Darkness, with Terra, while the heart of her past self that had inhabited the replica body found again its place in its time of origin.
- Saïx - Saïx was eliminated by Sora, Roxas and Xion. He admitted the reasons for his actions: he wanted first to find the girl called "Subject X" who served as guinea pig for the Ansem the Wise and Xehanort's experiments, but had finally succumbed to jealousy when Axel had become attached to Roxas and Xion. He was finally reconstituted to become Isa again.
- Ansem - Ansem was defeated by Sora, Riku and Mickey. He recognized Riku's true strength over the power of darkness, and as a Keyblade Master. Thus, Ansem's heart will return to its original era.
- Xemnas - Xemnas was defeated by Sora, Riku, and Mickey. Regaining his emotions, he reflected on the painful loneliness of the loss of his comrades, but ended up recognizing, thanks to Sora, that pain serves to remind humans that they are living. Thus, Xemnas' heart will return to its original era.
- Young Xehanort - Young Xehanort was defeated by Sora, Riku and Mickey. He taunts Sora on the dangers of the Power of Waking one last time before vanishing. Thus, Young Xehanort's heart will return to its original era.
- Replica Xehanort - Absorbed by Master Xehanort after their defeat against Sora, Donald and Goofy at Scala ad Caelum.
- Master Xehanort - Master Xehanort was defeated by Sora, Donald and Goofy. Nevertheless, the old Keyblade Master admits his defeat thanks to Master Eraqus, then a refugee inside Terra. Xehanort then hands over the χ-blade to Sora and finally joins Kingdom Hearts alongside Eraqus.
- As revealed in the Kingdom Hearts III Ultimania, the Thirteen Seekers of Darkness were original meant to have ranks like Organization XIII, but was changed in order to help avoid confusion with characters that had previous ranks in the original Organization.
- Members that were known to have ranks prior to this change were :
- I. Master Xehanort
- II. Xemnas
- III. Ansem
- IV. Xigbar
- VII. Saïx
- XII. Young Xehanort
- XIII. Xion (formerly Vexen)
- However, its not too farfetched to believe the remaining ranks went in the order of Vantias, Terra-Xehanort, Dark Riku (formerly Demyx), Marluxia, Larxene and Luxord.
- Members that were known to have ranks prior to this change were :
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