I'll be explaining the various kinds of enemies in the Kingdom Hearts universe, how they're created, what happens when they die, and what their goals are. If you feel you are very familiar with the details and lore behind these enemies, then this post is not for you. Over a long time playing the Kingdom Hearts games, I've notice many people left confused about these enemies, whether it be in real life, or online, so I'm making this post to hopefully clear up that confusion. Enjoy! (This is a part of my "Explained" series of posts. To view my "Time Travel Explained" post, click here, to view my "The Braig/Xigbar Situation Explained" post, click here, and to view my "The Realm of Sleep Explained" post, click here.) What are Heartless? Heartless are the main and first enemy type introduced in the Kingdom Hearts series. Most of them are ink black in color and only act on instinct. They can be seen in various of the many worlds and realms in the universe of Kingdom Hearts. The stronger your heart is with the darkness, the more powerful your Heartless you produce will be. There are two types of Heartless: Pureblood Heartless and Emblem Heartless. What goal do Heartless try to achieve? Heartless mainly attempt to find and devour hearts, whether it be the heart of people, or the hearts of worlds. When they devour the heart of a person, then that person becomes a Heartless as well. Heartless, along with other beings strong with dark powers, are able to use portals called Corridors of Darkness. This portals allow them to travel from world to world and from realm to realm. It is dangerous for just anyone to use these portals however, because it is exposing you to direct darkness and it could affect your heart. That is why Heartless mostly use them since they are beings of straight darkness. How are Pureblood Heartless created? Pureblood Heartless were the first types of Heartless to exist. Pureblood Heartless are also known as natural Heartless, since they exist from natural causes. There are two ways a Pureblood Heartless can be created. The first way that a Pureblood Heartless can be created, is when someone succumbs to the darkness in their heart. Once this happens, the darkness inside their heart will devour their heart, then that darkness becomes a Pureblood Heartless. The second way that a Pureblood Heartless can be created is simply by drawing partsof the darkness out of your heart. Only beings that are strong with the darkness are able to do this, such as Xehanort. For example, in Kingdom Hearts Birth by Sleep, Xehanort was able to create Neoshadow Heartless simply by drawing out the darkness in his heart. Similarly, Riku in the first Kingdom Hearts, was able to create an AntiSora Heartless simply by drawing out the darkness in his heart. Pureblood Heartless are simply darkness of the heart, made flesh. When a heart is unlocked or succumbs to the darkness, the darkness within comes out and becomes a Pureblood Heartless, and devours the heart while it's at it. When a Pureblood Heartless devours someone else's heart, then the darkness within that person's heart will come out and become a Pureblood Heartless as well. When Heartless devour the heart of a world, that world falls to darkness, meaning it ends up in the Realm of Darkness. How are Emblem Heartless created? Emblem Heartless were originally created by a machine made by Apprentice Xehanort, along with the other apprentices of Ansem the Wise. This machine reproduced the process in which Pureblood Heartless are created. This means that this machine was able to produce artificial Heartless by making hearts be consumed by darkness. Emblem Heartless are essentially darkness that has a trapped heart inside, unlike Pureblood Heartless which are essentially darkness that have devoured the heart and become one with it. Emblem Heartless can also be created when an Emblem Heartless consumes someone else's heart, just like how Pureblood Heartless are created when a Pureblood Heartless consumes someone else's heart. What happens when Heartless are destroyed? When you destroy a Pureblood Heartless, the heart within them isn't visibly/physically released, but it is definitely freed. The freed heart will eventually end up turning back into a Heartless. When a Pureblood Heartless is destroyed by a Keyblade, then it's freed for good. It goes into a sort of limbo state and waits for the corresponding Nobody to be destroyed so that it can combine back with the body and recomplete the original person. If the person has no corresponding Nobody, then all you have to do to recomplete them is destroy their Heartless (with a Keyblade) since their body is already waiting in the limbo state. When Emblem Heartless are destroyed, the corrupted heart that's freed will end up turning back into a Heartless, just like the Pureblood Heartless. Except the hearts are visibly freed. When Emblem Heartless are destroyed by a Keyblade, the heart is freed for good and goes into the aforementioned limbo state and waits for the Nobody counterpart to be destroyed, just like the Pureblood Heartless. If there is no Nobody counterpart, then all you need to do to recomplete the original person is to destroy the Heartless with a Keyblade. Them being destroyed by a Keyblade also allows Organization XIII to be able to collect the hearts before they get a chance to recomplete. What are Nobodies? Nobodies were the second enemy type introduced in the Kingdom Hearts series. They are mainly white in color, and they lack hearts. Many Nobodies also use Corridors of Darkness as well. Since they have no hearts, Corridors of Darkness are a huge convenience for them since they can use them without being affected. What goal do Nobodies try and achieve? Nobodies do not have a direct goal. Unlike Heartless, Nobodies have a sense of self, so they are basically free to do what they please. Most of them however, work together to achieve the one thing they truly want: their hearts. Since Nobodies have no hearts, they do not have emotions or feelings. They do however remember what it was like to have emotions and feelings. How are Nobodies created? When somebody loses their heart and become a Heartless, their body and soul fade away and wait for its Heartless counterpart to be destroyed by a Keyblade so the original person can be recompleted. If you had a particularly strong heart however, then your soul will continue living on inside of your body, therefore making your body live on as well. This is what a Nobody is. The stronger your heart was, the more humanoid and the more like you, your Nobody looks. People with slightly weaker hearts, become less and less human looking and take the form of creature type beings that somewhat resemble Heartless, other than the color differences. Organization XIII, a group of powerful Nobodies, are able to convert other powerful Nobodies into lesser, creature-type Nobodies, such as Dusks, as well, presumably using a machine to do so. What happens when Nobodies are destroyed? If a Nobody is destroyed, then it fades away. When someone's Nobody and corresponding Heartless are both destroyed, then that original person will return as a complete being, with heart, body, and soul all intact. (The Heartless needs to be destroyed by a Keyblade). If somebody didn't have a strong enough heart to produce a Nobody, then simply destroying their Heartless with a Keyblade will make them return since their body and soul, the things that would have created a Nobody, have already been destroyed. When you return as a complete being, you have all of your memories from when you were a Nobody as well as your old memories. You do not remember your time as a Heartless though. Other Information Nobodies are actually able to regrow hearts of their own. It is currently unknown what the specifics of this are and what the exact process is. Nobodies have the memories of when they were people. What are Unversed? Unversed are beings created by extremely strong negative emotions. They spawn from Vanitas and his emotions particularly, presumably because there is no other being with negative emotions as strong as his since he is a being of pure darkness. The negative emotions are so strong, that they take physical form, which is what Unversed are. Their goal is to do whatever Vanitas orders them to do, and when they are destroyed, their negativity flows right back into Vanitas. What are Dream Eaters? Dream Eaters are beings that exist and are born in the Realm of Sleep. They can also be created artificially. They are the Realm of Sleep's own personal way of darkness taking form as creatures. They are also the physical embodiments of dreams. They consume dreams. There are two types of Dream Eaters: Spirits and Nightmares. Spirits eat bad dreams, while Nightmares eat good dreams and plant bad ones. When they are destroyed, they seem to simply vanish, but Dream Eaters essentially work the same way dreams do since they are the physical embodiments of dreams, so all you'd have to do to get a Dream Eater to return after being destroyed is to dream it up again. That would be pretty difficult though since you can't really control what you dream about. Sora and Riku used fragments they collected from Nightmare Dream Eaters to artificially create their own Spirit Dream Eaters. The Master of Masters artificially created Spirit Chirithy Dream Eaters as well, probably using the same method as Sora and Riku. That is what we know so far about all the enemy types in the Kingdom Hearts universe. Now, I will explain various characters' involvements with these enemy types and how they relate to them. Sora In the first Kingdom Hearts, Sora stabbed himself in the heart with the Keyblade of Heart. This unlocked his heart, therefore making the darkness in his heart come out and become a Pureblood Heartless. When Sora stabbed himself with the Keyblade of Heart, he had Kairi and Ventus' hearts inside of him. This also created Sora's Nobody, Roxas. Roxas is a special Nobody since he was created by a unique circumstance. Since Sora had Ventus' heart inside of him, Ventus' heart went with his body and soul (Roxas) and went inside of Roxas. Kairi's heart returned to her body and she was recompleted. Since Kairi is a Princess of Heart, she has special light abilities. Since this is the case, she was able to purify Sora's Heartless and bring him back to his human form. Sora was able to return back to his human form without the need and use of his body or soul, which is an extremely unique circumstance. He had technically become a walking, talking heart, until Roxas returned to him. Another thing to mention is how Sora's Heartless had a sense of self. When you willingly give in to the darkness and become a Heartless, then your Heartless will have a sense of self. Roxas Roxas is the Nobody of Sora. He took on the appearance of Ventus since he has Ventus' heart inside of him. Roxas has since returned back to Sora, and Sora is complete again. Roxas lacks his memory from when he was Sora because Sora's time as a Heartless was so short. Kairi Kairi is one of the Seven Princesses of Heart, so she doesn't have any darkness within her heart whatsoever. Since this is the case, when her heart left her body, no Heartless was created. Her heart took refuge within Sora and was later returned to her body when Sora stabbed himself with the Keyblade of Heart and she was recompleted. Since she is a Princess of Heart and couldn't produce a Heartless, no Nobody was created either. Her body did not fade away since she had a strong heart, but it did not turn into a Nobody either since she had no darkness within her heart to turn into a Heartless, so her body stayed in a sort of comatose state until her heart returned to her. Like I stated before, she could not produce a Nobody since there was no darkness within her heart to produce a Heartless. But, when Sora stabbed himself with the Keyblade of Heart, Kairi's heart was released, which then created a Nobody of Kairi since Sora did have darkness within his heart. Naminé Naminé is the Nobody of Kairi that was created by Sora instead of Kairi, as explained above. Since she was not created by a body or soul, she technically doesn't exist and shouldn't exist, but she does anyway. It is an extremely unique and special circumstance. Since she was created by such a unique circumstance and has a unique bond with Sora since she was created by him instead of Kairi, she is able to manipulate Sora's memories and the people's memories who are close to him. She has since returned to Kairi and Kairi is a complete person again. As stated above, Roxas has no memories of his time as Sora because Sora's time as a Heartless was so short. Naminé lacks her memory of her time as Kairi for this same reason. Naminé doesn't have her memory of her time as Kairi because Kairi never even had a Heartless to begin with. Terra-Xehanort Terra-Xehanort, also known as Apprentice Xehanort, is Terra's body taken over by Xehanort and is being used as a host body for Xehanort. He worked as an apprentice under the scientist, Ansem the Wise, so he can get close to the technology and resources that he has. He tested on different people and their hearts to see what affects different tests had. All of his tests ended in the people's hearts collapsing. He locked these people up in cells in a dungeon and since their hearts were collapsing, the darkness within them came out and consumed their hearts and became Pureblood Heartless. Heartless were very rare before these experiments occurred. He then created another test. He put alive people and dead people in the cell with these Heartless. The Heartless went for the alive people, because they had hearts. This caused the Heartless to increase in numbers. Apprentice Xehanort, along with the other apprentices of Ansem the Wise, then created a machine. This machine was the machine stated earlier that artificially created Heartless, known as Emblem Heartless. Later, Terra-Xehanort turned most of the apprentices into Pureblood Heartless by stabbing them all with his Keyblade. He also succumbed to the darkness and became a Pureblood Heartless himself. Ansem, Seeker of Darkness Ansem, Seeker of Darkness is the Heartless of Terra-Xehanort. He was created when the Robed Figure let himself be consumed by the darkness in his heart, therefore becoming a Heartless. That is what Ansem, Seeker of Darkness is. He had a sense of self, just like Sora's Heartless did, because he willingly became a Heartless. He is one of the only people to retain a human appearance after becoming a Heartless. He has since been destroyed by Sora. Scar Scar gave into the darkness in his heart, which caused the darkness within his heart to come out, consume his heart, then turn into a Pureblood Heartless. Scar retained his regular appearance, much like Ansem, Seeker of Darkness. He also had a sense of self, because he willingly became a Heartless. After Scar's Heartless was defeated, a strange and unique phenomenon occurred. Beings known as The Ghosts of Scar were formed from the lingering darkness of Scar. It is unknown why or how this exactly happened, and it is unknown if these "ghosts" would be classified as Heartless or not, but they were able to merge together to create an Emblem Heartless known as a Groundshaker, which is an even stranger phenomenon that has no current explanation. Xemnas Xemnas is the Nobody of Terra-Xehanort, created when Terra-Xehanort succumbed to the darkness and became a Heartless. Xemnas has since been destroyed by Sora. Since both Xehanort's Heartless and Nobody have been destroyed, Xehanort has returned as a complete person. Vanitas Vanitas is the darkness from inside of Ventus, taken humanoid form. Ventus was used by Xehanort to try and fulfill his plan of recreating the χ-blade. To recreate the χ-blade, two beings, one of pure light, and one of pure darkness, need to clash. So, Xehanort extracted the darkness side of Ventus' heart from within Ventus and it took a physical, humanoid form, known as Vanitas. Since Vanitas is a being of complete darkness, without a single bit of light within him, he produces extremely strong negative emotions. These negative emotions are so strong, that they take physical forms, known as Unversed. Riku In Kingdom Hearts 3D: Dream Drop Distance, Riku is considered to be a Dream Eater, because he has the ability to dive into Sora's dreams, and defeat the bad dreams, just like a Spirit Dream Eater would. That's it! I hope this was able to help anyone who was puzzled or somewhat confused with any of the enemies in the Kingdom Hearts universe :) Feel free to ask any questions in the comments below.