Xigbar is one of the most important characters in the Kingdom Hearts franchise, playing an important role in many of its games. At the end of Kingdom Hearts 3, players learned of a shocking revelation surrounding Xigbar's character that has made people think he will be one of the main antagonists in the Lost Master arc that'll pick up steam in Kingdom Hearts 4, along with the Master of Masters.
Kingdom Hearts 4 is the next game to release in the Lost Master arc, and fans have speculated what Xigbar's role could be as they learn more about his past through mobile games, Kingdom Hearts: Union X and Kingdom Hearts: Dark Road. It seems that he will not be leaving the series any time soon and there are many possible directions that his character can go in to advance the plot.
Xigbar's Role In Previous Games
Chronologically, the first game that Xigbar appeared in was Kingdom Hearts X. However, back then, he was known as the Master of Masters' sixth apprentice, Luxu. The Master of Masters gave Luxu the incredibly important task of traveling around with No Name, the keyblade that contained his eye. Luxu would eventually pass No Name down to a successor, allowing the Master of Masters to see into the future and write the Book of Prophecies. The Master of Masters then gave each of his other apprentices a copy of the Book of Prophecies, as well as a role that would lead them to fight against each other in the Keyblade War, making it so Luxu is arguably responsible for the deaths of hundreds of keyblade wielders.
After the Keyblade War, Luxu began possessing people in order to live for generations, eventually taking on the form of Xigbar. As Organization 13's second in command, Xigbar assisted Xehanort in his battle against the Seven Guardians of Light. During the fight, Xigbar faked his death and waited for No Name, which was in Xehanort's possession, to return to him. Once it did, Xigbar summoned the Master of Masters' other apprentices, with the exception of Ava, at the end of Kingdom Hearts 3, leaving fans to wonder what would be next for Xigbar and his comrades.
The Worlds That Xigbar May Go To In Kingdom Hearts 4
Since Xigbar brought the Foretellers back, it is very likely that his next move will involve reuniting with the Master of Masters as well, who is currently in Quadratum. Quadratum will likely be the main setting of Kingdom Hearts 4 as Sora was seen there in the game's trailer. Sora's friends have been trying to track him down since he disappeared at the end of Kingdom Hearts 3, so Xigbar could use them to find his master. Upon their reunion, Xigbar, the Master of Masters, and the Foretellers would probably fight against Sora, Riku, and any of the other protagonists that go to Quadratum, leading to an epic showdown where the Guardians of Light would learn of the danger beyond Master Xehanort and the Seekers of Darkness.
Another possibility is that Xigbar and the Foretellers will not go to Quadratum at all. The Master of Masters may have given them another role to fulfill in other worlds while he is in Quadratum. Through Kingdom Hearts 3's ReMind DLC and Kingdom Hearts: Melody of Memory, fans have learned what many of the heroes have been doing in order to find Sora. Terra, Ventus, and Aqua have searched the Realm of Darkness, King Mickey is investigating in Scala ad Caelum, and Donald and Goofy are going on a new journey themselves, as seen in the trailer for Kingdom Hearts 4. Xigbar and the Foretellers may go to one or more of these worlds in Kingdom Hearts 4 to fight against Sora's friends while he's gone.
Xigbar Could Take On A New Form In Kingdom Hearts 4
It is also possible that Xigbar will take on another form by the end of Kingdom Hearts 4, getting rid of the vessel he's had since he was introduced. In order to hurt the Guardians of Light, he may even possess one of them, such as Sora, Riku, or Roxas. Xigbar has had his eye on the protagonists for a long time now. In fact, he and the other members of Organization 13 had intended on using most of the heroes at some point to achieve their own goals, so it would make sense if Xigbar takes his next vessel from of a beloved character.
Some fans have wanted to see Sora turn to darkness and for Riku to rely on his darkness as much as he did in the earlier games of the series. If Xigbar were to possess one of them, that wish could come true, as players would need to battle against the protagonists they once played as. There's also the possibility that Xigbar would possess someone that he knew from one of his previous forms, such as Ventus, Larxene, or Marluxia.
Xigbar Could End Up Being A Hero
While it is heavily speculated that the Master of Masters is the next main antagonist of the series, fans do not actually know what his intentions are. Players were surprised to discover that Xehanort actually had justifiable reasons for all the things he had done, and the same thing could happen with the Master of Masters. If this is the case, then Xigbar may have been helping his master do something noble this entire time.
Lastly, it was discovered in Kingdom Hearts: Union X that Luxu was the traitor that the Master of Masters had prophesied. Fans still aren't completely sure what this means, but one possibility is that Xigbar will end up betraying his master, who has anticipated it all along. Perhaps Xigbar will actually join forces with the Guardians of Light to defeat the Master of Masters, if he proves to be the villain that many fans think he will be. There are many possibilities for what Xigbar will do in Kingdom Hearts 4, but no matter what path he takes, he will likely play an important role throughout the Lost Master arc.
Kingdom Hearts 4 is currently in development.