"The Ultimate and original Keyblade of the Dark Realm"
|Dark Emperor, Dark Emperor's reincarnations|
|Absolute power over Darkness|
To open the Door to Darkness
Fallen Deity is a legendary weapon in the shape of a Keyblade, but in truth it is a similar weapon to the χ-blade. It is the original Dark Keyblade, in turn being a Keyblade that was broken by Darkness' whim and fundamentally rebuilt by it on the molecular level, giving it absolute divine power and unity with the powers of Darkness.
While the χ-blade exists to coexist with Kingdom Hearts, Fallen Deity exists to coexist with the Primordial Darkness that has always existed. As Keyblades of Light are man-made weapons inspired on the χ-blade, Dark Keyblades are corrupted Keyblades that have also been reforged in the power of Darkness, in inspiration for the recreation that Fallen Deity underwent.
Fallen Deity, and its Dark Keyblade children, are the aligned Keyblades of the Realm of Darkness.
The Fallen Deity Keyblade has a spiky, black guard resembling demonic wings, a horned lion head just above the handle, two barbed shafts, and teeth resembling a battle axe split into three almost claw-like protrusions. It resembles the Oblivion Keyblade to a degree, but with two shafts and a different head. It also contains two eyes of darkness; one above the handle and the other one on the head. Its shaft and head are adorned with several twisting, silver patterns.
- Currently, in Kingdom Hearts' canon, this Keyblade is Master Xehanort's Keyblade and is named thus.