Sixteen Realms

The Sixteen Realms, also known as The Realms of Creation, are collections of worlds, all connected to the Kingdom Hearts.

Lore (according to Metallix)
Each one of the worlds is part of a realm, and each realm is has it's own reality. There is a total of sixteen realms (although Metallix only detected fourteen because two of them were destroyed by the time the Olympics at Disney Town took place). Each realm has a sister, meaning that the destruction of a realm leads to the destruction of it's sister realm. For example, the Realm of Light and the Realm of Darkness are sisters, meaning that, if either light or darkness would take over all of their worlds, the opposite realm would be destroyed, and the winning realm will be destroyed as well shortly afterwards. However, Metallix says it's not the case for those two realms, due to Dimension Metallix, which is part of the Realm of Darkness, being impossible to bring back to the light due to Robotnik playing with reality, and, likewise, the NEO Prime Zone, which is part of the Realm of Light, being impossible to bring to the darkness due to Dr. Koopa playing with reality. However, a Super Genesis Wave might be able to destroy a realm and it's sister, meaning that Robotnik, with his playing with reality, nearly destroyed both the Realm of Light and the Realm of Darkness, and should Dr. Koopa not have absorbed his own Genesis Wave, the realms would most likely have been destroyed, and the events of Freedom Fighters NEO and it's semi-canon spinoffs would never have taken place.

The worlds are extremely various, each one having it's own type of inhabitants. For instance, nine of the realms are inhabited by living LEGO, which are popular toys in the Realm of Light and on the Other Side. The Prime Zone and most variations of Mobius exist within the Realm of Light, except for those in which Robotnik won, such as Dimension Metallix, which exist within the Realm of Darkness, and a dimension in which all Sonic characters are made of LEGO. Most variations of Earth as Rock, X and Zero knew, as well as most variations of the Mushroom Kingdom, exist within the Realm of Darkness, each for it's own reason. Most of the Disney Worlds exist within the Realm of Light. In fact, most of the events of Freedom Fighters NEO and it's semi-canon spinoffs take place in the Realm of Light.

List of Realms

 * Realm of Light (sister of the Realm of Darkness)
 * Realm of Darkness (sister of the Realm of Light)
 * Realm Between
 * Realm of Sleep
 * Other Side
 * Ninjago
 * Underworld
 * Realm of Madness (not to be confused with the similar Realm of Darkness)
 * Cursed Realm (destroyed by Ninjago's Master of Water)
 * Cloud Kingdom
 * Chima
 * Djinjago (destroyed in consequence to the destruction of the Cursed Realm)
 * Departed Realm
 * Realm of Oni and Dragons
 * Never-Realm
 * One unknown realm

Means of travel
There are various means to travel between realms; however, most of them originate from Ninjago, and aren't well developed, due to Ninjago only being explored in the last two sagas. There are nine better developed means of travel between realms:


 * Piloting a Gummi Ship; as Gummi Ships are composed of fragments of shattered barriers, they are capable of passing through them.
 * The Star Shards. The downside to this method of travel is that if the user does not know how to control the shard, the destination and time of activation will be random.
 * Utilizing the Corridors of Darkness; this is a faster means of travel than the Gummi Ships, but those who use them are at great risk of being corrupted or destroyed by the darkness.
 * Teleportation, used by beings that possess powerful magic.
 * Keyblade Glider; Terra, Aqua, and Ventus can change into their armored form and turn their Keyblades into vehicles that can travel to other worlds by using the Lanes Between.
 * Sufficiently powerful Keyblade wielders are able to open portals to the lanes to allow access to different worlds, as shown with Dr. Koopa who built a some teleporters between the Prime Zone, Disney Town and the world of Lilo and Stitch, and further created more of these teleporters in the other Disney Worlds.
 * Time travel, which can take you between various dimensions. The downside of this method is that you cannot leave the realm you're within.
 * Keystone Devices created by Lord Vortech.
 * Death is stated to be taken to a higher plane of existence, implied to be the Departed Realm.
 * The Space, Time and Reality Stones. The Space and Time Stones have a downside: you cannot leave the realm you're within. The Reality Stone, however, doesn't have this downside, and allows travel to other realms as well. This method of travel is the most efficient if you have all three of these stones. Only Metallix can use it more efficiently, since he guards both the Reality Stone and six of the Time Stones.

Misconceptions
A misconception is that all ghosts originate from the Cursed Realm, all skeletons originate from the Underworld, and all genies originate from Djinjago. The Merger Magikoopa cleared this misconception as follows:


 * Boos (a type of ghosts) and Dry Bones (a type of skeleton) originate from the Realm of Darkness.
 * Skeletons and ghosts that originate from the Monster Kingdom originate from the Realm of Light. The Gasters are such skeletons, and Mettaton and Napstablook are such ghosts.
 * Genies truly originates from the world of the Arabian Nights, which exists within the Realm of Light, being a Disney World. The only genies that originate from Djinjago are those made of LEGO. Since Djinjago is destroyed, LEGO genies no longer exist.
 * Similarly, a misconception is that all dragons originate from the Realm of Oni and Dragons. The Merger Magikoopa stated that the Realm of Oni and Dragons being the first realm created is a lie fed to the inhabitants of Ninjago, and that, in truth, the first two realms existent were the Realm of Light and the Realm of Darkness. The other fourteen realms were created in the Keyblade War. This implies that the First Spinjitsu Master was a Keyblade Master.