Kingdom Heartless: Shadows Among Us

Kingdom Heartless: Shadows Among Us is a story about a genetic Heartless with a Keyblade named Treble who is a edgy Heartless destined to stop a new foe from halting the balance of light and darkness despite Treble having dark abilities.

The Edge of the World
Many human-heartless hybrid scientists of the Heartless World called The Edge of the World were developing Heartless inside their labs, creating new breeds. That is until they have created a new Heartless, one that is balanced by light and darkness, those of Sora and Roxas and Ventus combined, with the power of darkness infused and the genes of many Disney villains such as Maleficent, Jafar, Hades, Ursula, etc. and those of the Nobodies such as Xemnas, Saix, Luxurd, Xigbar, and Xaldin. They created Treble, a purple heartless that is a edgy yet loyal heartless to the human-heartless hybrids.

During the past 2 years, Treble stayed with the humans because of his loyalty and due to the fact he gained a friend named Iris who is sicken with a neuron virus causing her to lose her memory and eventually die from it. Unfortunately, a uprising began and thus a rebellious group known as Mavericks that are consisting of human-heartless hybrids waged war against their own kind. Treble battles them only that when he is exhausted from battle, Iris steps in and took a stab from a sword which in turn, she detonated into a nuclear explosion, destroying all of The Edge of the World and yet Treble survived. Enraged by the Mavericks' uprising, Treble vowed vengeance and traveled the world of the worlds to put a end to their reign.

Beast's Castle
Treble warps to Beast's Castle and ended up encountering Beast which afterwards Beast ran off to help the distressed Belle. Then Trebles gains a dark ability to summon Lesser Heartless into battles and was given a tutorial to do so. After finding Beast, they agreed to help each other after Belle was kidnapped by a Maverick called Varis.

Once they have found Belle, Varis trapped them and both Treble and Beast battled the Mavericks but as the battle was getting Treble to the point where he has no choice, he draws out his Keyblade and Beast notices that Treble was not the only one wielding a Keyblade. Treble summons his Heartless allies being Shadows and some Gargoyles. Treble defeated Varis and they rescued Belle and also, Beast was reverted back to his human self.

Beast asks Treble to use his Keyblade to unlock the door that has a keyhole which is much different than the other keyhole and rescued his servants who are also reverted back to human form. Treble warps away to continue his vengeful mission.