Kingdom Key D

Mickey's Keyblade is a Keyblade that is an alternate version of the Kingdom Key. It is called the Keyblade of the Realm of Darkness. This Keyblade of the Realm of Darkness was found there.

It did not always belong to the King. Before Kingdom Hearts, he previously wielded the Keyblade Star Seeker, as shown in Birth By Sleep, most likely when he was still an apprentice of Master Yen Sid. In addition, this Keyblade was shown in the secret ending of Kingdom Hearts II called The Gathering, along with Sora's Kingdom Key and Riku's Way to the Dawn. Notably, these three Keyblades, along with Master Xehanort's keyblade, are the only ones in the movie shown with Keychains. It is unknown exactly how the King obtained the Keyblade of the Realm of Darkness by the end of Kingdom Hearts. He does not have any sort of weapon, except for his wits, in Timeless River.

It was originally seen in the closing video for Kingdom Hearts. It is expected to appear in Kingdom Hearts coded.

Trivia

 * Since this keyblade is the inverse of the regular Kingdom Key it can be assumed that when a keychain is attached to alter it's form the keyblade, such as Oblivion, would have inverse colors.