Weapons fashioned in ancient times int he image of the χ-blade in order to fight back the darkness and maintain order in the World. Keyblades can only be wielded by chosen individuals who are strong of heart.
Shaped like keys, they operate any lock in existence, and are imbued with magic and other unique capabilities. Keyblade wielders may "bequeth" their powers to the next generation upon meeting worthy individuals.
A title reserved for the select few who have prove their knowledge and skill with the Keyblade is sufficient to protect the order of the World.
The Keyblade War[edit source]
An epic clash in the distant past, when the forces of light and dark fought for control of Kingdom Hearts—the collective hearts of every world—and the χ-blade that serves as its key. The battleground upon which the war was fought is now known as the Keyblade Graveyard, a barren place where Keyblades just from the ground like tombstones.
Master Xehanort seeks to recreate the Keyblade War in order to forge the χ-blade, unlock Kingdom Hearts, and learn what mysteries await in the world beyond.
The χ-blade[edit source]
An implement created as a counterpart to Kingdom Hearts, and the only key that can open it. All other Keyblades are believed to have been created in its image. The χ-blade was destroyed during a great battle in the past. It will be reforged when seven hearts of pure light clash with thirteen pure darknesses.
In the past, Master Xehanort divided the darkness and light in Ventus's heart and pitted them against one another, artificially creating a χ-blade, but his experiment failed and the incomplete blade was destroyed.
Foot soldiers in the forces of darkness. They can appear in any world, and attack those living there in order to steal their hearts.
The Heartless are formed when a person's heart is separated from their body and the darkness in the heart takes physical shape. They act autonomously, and their attacks are able to corrupt even those with hearts of light, giving rise to new Heartless in turn.
A Keyblade can free these stolen hearts from the darkness, and so Sora travels the worlds actively seeking out Heartless to defeat.
Heartless can be roughly divided into two categories: Purebloods, the original strain, and Emblem Heartless, which were artificially created.
Embodiments of emptiness that serve the darkness. Nobodies arise alonside Heartless, when the empty body left behind becomes its own autonomous creature.
Nobodies who possessed exceptionally strong hearts in life may retain their original appearance, as did all of the previous Organization XIII members. Not everyone fares so well, however; most bodies cease to exist the moment their hearts are lost. As a result, Nobodies are fewer in number than their Heartless counterparts.
Creatures aligned with the darkness. They arise from powerful negative emotions, and when defeated, they return to the source of pure darkness from which they came: Vanitas.
The Unversed's presence in a location is clear evidence that Vanitas is somehow involved. So long as their master continues to exist, they will spawn endlessly.
Creatures native to the Sleeping Worlds that feed on dreams. Two types exist: Nightmares that eat good dreams and plant bad ones in their stead, and Spirits that eat only bad dreams. The Spirits have fought alongside Sora and Riku in past battles.
In the age of fairy tales, Spirits called the Chirithy once provided assistance to Keyblade wielders.
A group of thirteen powerful Nobodies who retained their human appearance, led by Xehanort's Nobody, Xemnas. They attempted to create an artificial Kingdom Hearts by gathering hearts released from fallen Heartless, but Sora and his friends thwarted their plans and put an end to most of their ranks.
The members of Organization XIII were recompleted as humans after their destruction. Like Sora's newfound ally Axel, they retain memories of their lives both during the Organization and before.
Many members are recognizable from the old Organization. Despite regaining their humanity after their defeat, they chose to become Nobodies again. They now scour the worlds for candidates to complete their numbers.
The Three Realms[edit source]
Worlds in the realm of light and realm between exist as planets in a great sea of stars, which Sora and his friends explore aboard their smile-power gummi ship.
The realm of darkness, however, exists in a space closed off from time. It is accessible only via dark corridors—pathways that open for agents of darkness, or when worlds become unstable—or by using the "power of waking." As a result, Aqua has spent years wandering the realm of darkness, unable to return to the light.
Artificial simulations based on real-world data. Inside a datascape, time can be made to loop infinitely, and the impossible becomes possible.
Donald's magic ensures that Sora and his fellow travelers will always assume an appropriate form for the worlds they visit, so as not to disrupt the local order.
In general, the guardians of light take the utmost care not to spread knowledge of other worlds to the residents of the places they visit—or at least they try. Sora has a habit of forgetting, and every slip of the tongue earns him a fresh lecture from Donald.
In Yen Sid's worlds, "the power to free a heart from its sleep." By the end of his Mark of Mastery examination, Sora had acquired the power of waking, but he lost it when he nearly became a vessel for Xehanort.
Lost Memories[edit source]
Sora's memories of his adventures at Castle Oblivion in the realm between, and of the members of Organization XIII he faced there. In the end, he cast aside his memories of Castle Oblivion and fell into a deep slumber in order to repair the original memories he'd lost.
The Nobodies of Organization XIII were unaffected by the castle, and still retain unilateral memories of their encounters with Sora there.
A research project that was helmed by Vexen when he was part of the original Organization XIII. The goal was to create empty vessels that could contain a heart and outwardly reflect its original appearance.
The previous Organization used the replica to copy Sora's memories, hoping to give life to a Keyblade wielder of their own. But while Vexen did manage to make viable specimens, the program was cut short before it could reach completion.
The Black Box[edit source]
The object of Maleficent and Pete's search. Maleficent believes it has been hidden away since the age of fairy tales, but no one knows where it is or what exactly it contains.
The Old Words[edit source]
A phrase oft intoned by Keyblade users in the age of fairy tales. The words live on today, though few still recite them.