Unknown Keyblade Master (Another Path)

The Unknown Keyblade Master is a similar being to the Unknown from Kingdom Hearts: Birth By Sleep, he appears briefly in Kingdom Hearts: Another Path at the Drifting Darkness which becomes the End of the World prior to Another Path's post game Ten year timeline straying over into Kingdom Hearts: Another Story, by the end of Another Path his name is revealed to be Blaid Dark which it states that he has a higher purpose in the follow up games of this Xehanort's Saga branch-off.

Biography
Little is know about the Unknown Keyblade Master other than he trained Mauro and has been seen to push towards Xehanort's success for the benefit of some unknown purpose, the Unknown Keyblade Master states that the Realm In-Between is his domain which governs the Darkness witin the Realm of Light and that a war is soon approching where the Realm In-Between would become a Warzone and a condoit for those of the Dark Realm to pass through.

He is fought on the optional level: the "Drifiting Darkness", where he can be bested as Lepton similar to how Mauro fights Eraqus' Lingering Spirit as an optional boss however he is noted to be a Master of Dark Magic and the battle ends once his life force is depelted, the Unknown Keyblade Wielder dismissing Lepton in a blast of Darkness energy before cloaking the "Drifting Darkness" in a thick shield of Dark Mist to stop return to that world.