Kingdom Hearts Transformers is a reboot to the Universe XP Kingdom Hearts series that actually has better grammer and more explanation to why many human heroes and villains are supposedly transformers in the series. AND...it actually admits that it has more influence on Transformers than it does with Kingdom Hearts.
It is the year 2005, and the treacherous Decepticons have taken over the planet Cybertron from the Autobots. But now the Autobots have found a new way to retake their planet from their hated enemies. By mining in Earth's deep caves, they have discovered a new energon source that can transform their bodies into new and more powerful forms. It can also change human beings with special powers into Transformers themselves. Thankfully for the heroes, they can change back into their human forms with a special key that they are given before the transformation begins. With this new energon called Ore-13, the Autobots have summoned forth the galaxy's mightiest heroes, and have given them the energon to change them into honorary Autobots so that the Decepticons can be defeated at last. But the terrible Decepticons have managed to find several Ore-13 mines, and have enfused their mines with Dark Energon so that they can have their own dark forces of honorary Decepticons to counter the honorary Autobot forces. Now the Autobots, their new recruits, and the Decepticons fight the Great War anew with new weapons and technology to help them out. Til All Are One!
The Autobots are still led by the valiant Optimus Prime, who has now been given the task of teaching Sora the keyblade wielder everything he needs to know of being a leader before the two can finally unite to take down Megatron.
The Decepticons are still led by Megatron, who remains as power hungry as ever, but now he has to contend with Maleficent, the Mistress of Evil, and Xehanort, Seeker of the Night, for leadership over the Decepticons.