Kingdom Hearts Birth by SleepEdit
As his orginal self, Braig, he allied himself with Master Xehanort in order to gain a Keyblade. He staged a kidnapping of the elderly Keyblade Master to draw out Terra's inner darkness; however, this left him the left side of his face scarred and sporting an eyepatch over his right eye. Though angered by his injuries, Braig was clamed by Master Xehanort who then placed a fragment of his own heart in him, slowly beginning the process of turning him into one of the Thirteen Seekers of Darkness needed for his plan to create the X-blade; he was willing to let this happen as upon complete transformation, he would get a Keyblade at the cost of his own personality. He later appeared at the Keyblade Graveyard, battling Aqua after being glared at by Ven for mocking them. After returning to his world, Braig is the first of Radiant Garden's residents to find Xehanort, befriending him as they became apprentices to Ansem to begin the next step in their plan.
Between Birth by Sleep and 358/2 DaysEdit
He assisted Xehanort in experiments creating the Heartless to find a way to make the mind surrender its sense of self and make it a suitable host for a fragment of Xehanort's heart. However, Xehanort seemed to grow impatiant with the lack of results and removed not only the hearts of the other apprentices, but Braig's as well. This resulted in the creation of Xigbar, a Nobody lacking any heart accept the fragment of Master Xehanort's. Because of this fact, Xigbar is the only Organization member who knows Xemnas' true intentions, but believes he'll fail in being one with Kingdom Hearts . Xigbar controls Sniper Nobodies, and attacks with a pair of Arrowguns called "Sharpshooter", which can be combined to form a sniper rifle. Xigbar can also manipulate space to teleport himself, warp his bullets, and levitate in battle.
He is also the one who found Marluxia and brought him into the Organization; however, he doesn't know how to pronounce his name. Xigbar also often easedrops on Xemnas and the others, learning of their secrets.
Kingdom Hearts 358/2 DaysEdit
When the Organization recieved their thirteenth member, the Nobody of a Keyblade weilder that barely had a sense of self, it seemed "Roxas" would be a perfect candidate for Master Xehanort's plan; however, Roxas developed a mind of his own over time. Xigbar drops several hints to Roxas about his true nature  He finds out about the Replica Project much sooner than most of the members, and takes it upon himself to monitor Xion. Xigbar battles Roxas at the Olympus Coliseum in the middle portion of the game to test his strength during a mission, much to the chagrin of the latter . Later while assigned in Wonderland with Axel and Xion, Xigbar fights the latter as she leaves the Organization, smirking how she assumed the form of Ventus from his perspective.
Kingdom Hearts IIEdit
Upon Sora's awakening from a year of slumber, Xigbar faces him in Hollow Bastion near the beginning of the story, though he never takes off his hood. He compares Sora's galre to Ven's, confusing and angering the Keyblade weilder. Though it would seem he's going to fight, Xigbar promptly flees, telling Sora to be a good boy. When the Organization is meeting to discuss their plans to manipulate Sora into feeding their Kingdom Hearts more hearts from slain Heartless, Xigbar suggests Demyx go to the Underworld to either make a deal with Hades or awaken Roxas within Sora; he fails in both attempts. During the player's second visit to the Land of Dragons, he transforms a dragon into a powerful Heartless to collect more hearts, and leaves after Sora confronts him in the Emperor's Palace, summoning his Nobodies to cover his escape.
When Saix summons droves of Heartless to kill Sora, Xigbar elimminates them all to take on Sora himself. After calling Sora "Roxas", and cryptically mentioning Sora wasn't as good as Terra, Aqua and Ven, he starts fighting him with all his strength. However, he is defeated and refuses to tell Sora why he called him Roxas. Unlike other members of the Organization, Xigbar faded away with a smile.
Kingdom Hearts Dream Drop DistanceEdit
Despite his desturction, Xigbar returns, thus it is why Braig didn't show up in Radiant Garden with Dilan, Even, Aeleus, Ienzo and Lea. Having been pulled out of the past by Young Xehanort, Xigbar takes the Number 4 seat of the True Organization XIII. Tasked with vexing Sora and leading him deeper into the abyss of sleep, Xigbar and Xemnas reveal the truth of Organization XIII's founding and that Nobodies could develop new hearts. When Sora showed enough strength to fight back against their attempt to turn him into their thirteenth needed vessel for Master Xehanort's heart fragments, Xigbar left Xemnas to weaken and put Sora to sleep. At this point, as Xigbar himself says, he has become half-Xehanort.
When Riku attempts to rescue Sora, Xigbar appears along with the rest of the Organization as Young Xehanort explains their plan to the Keyblade weilder. He is frozen in time by King Mickey, but is freed once the King's magic wears off. Unlike Ansem, Seeker of Darkness and Xemnas, Xigbar doesn't try to do anything to contribute to stopping the heroes. He is shocked by Lea's arrival, mistaking him for Axel, angered that the Organization was prevented from complition (Lea's fire blocked the heart fragment fired at Sora). As they would have to go back to their own times until Master Xehanort called for them again, Xigbar wondered what the Old Coot had planned now. This prompted Saix to attack in an unsuccessul attempt to retireve Sora. Xigbar then returned to the past to await Master Xehanort's call to fore the X-blade.