What is time travel in the Kingdom Hearts universe? Well, it's like time travel from any other game, movie, or show. It's where you leave your present time and move either backwards or forwards to a different time. How does somebody time travel in the Kingdom Hearts universe? First, you must abandon your body and become just a heart. One way to become just a heart is to extract your heart with a Keyblade. Once you become just a heart, then you have the ability to move through time. What are the laws of time travel in the Kingdom Hearts universe? You are only able to travel through time if there is a version of yourself present at the time you want to travel to. Also, you cannot change what is destined to happen. Once you return back to your respective time, you will forget everything that has happened during your experience time traveling. However, these memories and experiences will be etched into your heart and could influence your decisions and the paths you take. That is what we know so far about time travel in the Kingdom Hearts universe. Now, I will explain various characters' involvements with time travel Terra-Xehanort Terra-Xehanort is Terra's body taken over by Master Xehanort. He apprentices under Ansem the Wise so he can further study the darkness and get access to things that could potentially help him further gain powers of the darkness. He steals Ansem's name, then he gets rid of his body and becomes just a heart, by extracting his heart with his Keyblade. This heart sort of "half" becomes a Heartless, known as the Robed Figure. Robed Figure/Ansem, Seeker of Darkness The Robed Figure is the Xehanort's reduced to just a heart, like stated above. Since he is just a heart, he is able to travel through time. He goes back in time to Destiny Islands, where he meets a young version of himself. He explains to him that he is his future self's heart and basically explains to him everything that happens in the future and what his future plans are. Since this young version of Xehanort now knows how to time travel because Ansem, Seeker of Darkness told him how, he is sent on his way through time. The Robed Figure later willingly lets his heart be consumed by darkness and then he becomes a full and complete Heartless, known as Ansem, Seeker of Darkness. Young Xehanort As explained above, Young Xehanort now has the ability to travel through time. The plans that the Robed Figure/Ansem, Seeker of Darkness have explained to him is that he has to go through time and bring with him various versions of himself and some followers who have been loyal to him before. He goes through time, and watches all of the main cast from the very beginning, and plans everything out. He gathers 10 versions of himself and brings them to the present day. Out of those people, the current known ones are Xemnas, Ansem Seeker of Darkness, Xigbar, and Saïx. These are all people who are deceased in the present time. Master Xehanort Master Xehanort is the one who took over Terra's body, as explained above. He has returned to the present day because Xemnas and Ansem, Seeker of Darkness have been destroyed, which are his Nobody and Heartless. Once someone's Nobody and Heartless are destroyed, the original person is revived. Master Xehanort gathers with Young Xehanort and the 10 people that Young Xehanort had gathered. Xemnas Xemnas is the Nobody of Terra-Xehanort. He was destroyed by Sora. He has now been brought back to the present day by Young Xehanort. Ansem, Seeker of Darkness (pt.II) Sora has destroyed him. Young Xehanort brings him back to the present day. Xigbar Xigbar is the Nobody of Braig. Xigbar has been destroyed by Sora, and has revived as Braig, but he has been turned back into a Nobody by Xehanort. He has not been revived by time travel like many think. Saïx Saïx is the Nobody of Isa. Saïx has been destroyed by Sora, and has revived as Isa, but he has been turned back into a Nobody by Xehanort. He has not been revived by time travel like many think. Extra Info Xehanort's plan has been to gather 13 vessels that all would bear a piece of his heart inside of them. This was Xemnas' plan with Organization XIII, but a few of the members he had gathered were inadequate. This is what lead to the various new people that Young Xehanort had been gathering. He gathered 10 people and along with himself and Master Xehanort, that makes 12 people. Their original planned 13th member was Riku, but he became immune to the darkness, so he was of no use to them, then they chose Roxas, but he became too aware of himself. Now, they moved down to Sora. They were able to capture him, but he had been saved. They are currently missing a 13th member for their new Organization XIII and will soon find a replacement. Sora and Riku In the beginning of Kingdom Hearts 3D: Dream Drop Distance, Sora and Riku traveled back in time to the day Destiny Islands fell to darkness. This happened simply because of Yen Sid's magic. But like Xehanort's method of time traveling, Yen Sid is only able to have them go to a place in time where they exist. Timeless River In case anybody was wondering, no, Timeless River has nothing to do with any of this. Timeless River is a completely separate time anomaly that brings you to the world of Disney Castle before Disney Castle has been built.