Kingdom Hearts was first released in 2002, and in nearly twenty years, the series has added many prequels and sequel games, which further expanded the Kingdom Hearts lore. For these games, Xehanort was the franchise's main antagonist and is responsible for many key events during the Dark Seeker Saga storyline. Throughout the complex timeline, different versions of Xehanort would appear in several games within the series. With so many variations of the same character, here's an explanation of all the different versions of Xehanort in Kingdom Hearts.
Master Xehanort was first introduced in Kingdom Hearts Birth By Sleep and is the original version of the character. More of Xehanort's past was revealed in Kingdom Hearts Union X and Kingdom Hearts 3. Xehanort was once a young Keyblade Master who was obsessed with how the world was first created by darkness. As time passed, Xehanort manipulated events throughout the story in order to accomplish his goal to recreate the world.
In Kingdom Hearts Birth By Sleep, Master Xehanort needed to replace his aged body with a new younger one. Through manipulation, Xehanort transferred his soul and consciousness into another Keyblade wielder named Terra. Xehanort's possession of Terra's body is known as Terra-Xehanort, or Terranort. With a new body, Terra-Xehanort planned to enact his goals but was defeated by Aqua. After his battle with Aqua, Terra-Xehanort suffered amnesia. Having forgotten everything, Terra-Xehanort was taken in by Ansem the Wise and became his apprentice.
How Kingdom Hearts' Xehanort Was Split into a Heartless & A Nobody
Prior to the events in Kingdom Hearts, Terra-Xehanort become curious about the darkness within human hearts and began performing experiments. This led to him becoming a Heartless known as Ansem the Seeker of Darkness, who was the main villain in the first game. Ansem the Seeker of Darkness lacked a physical form and a needed new vessel. Throughout the events of Kingdom Hearts, Ansem manipulated Riku, eventually succeeding in possessing his body. Ansem the Seeker of Darkness was later defeated by Sora, Donald, and Goofy, which led to Riku's freedom.
A Heartless is a manifestation of a person's heart when consumed by darkness. When a character transforms into a Heartless, the body is separated from the Heart and becomes a Nobody. When Terra-Xehanort became a Heartless, his Nobody named Xemnas was also born. Xemnas is the leader of Organization XIII and was the main antagonist in Kingdom Hearts 2. Lacking a Heart, his goal was to create an artificial copy of a world called Kingdom Hearts in order to become whole again. Xemnas was eventually stopped by Sora and Riku during the final battle in KH 2.
Young Xehanort was introduced in Kingdom Hearts 3D: Dream Drop Distance and is the time-traveling younger version of Master Xehanort. Young Xehanort was given the power to traverse through time by Ansem the Seeker of Darkness, in order to fulfill Master Xehanort's secret plan. He eventually becomes one of Master Xehanort's thirteen vessels and frequently appears throughout the story to oppose Sora and his friends. Xehanort's story was officially finished in Kingdom Hearts 3, but with future games confirmed, there's always a possibility he can return in some way.