Xthanan

Ranked as XVI in Organization XIII, Xthanan is the only member to exclusively wield darkness. He resides with the group in Minipeg. Mandroxa occasionally refers to him as "The Negative Influence".

Origin
Xthanan was inducted into Organization XIII at the same time as Mandroxa when they were found by Xigbar.

Key Plot Points
Mandroxa lost his heart after he tried to save Xthanan from a Mad Dog Heartless. His sacrifice to save his friend proved to be futile, as Xthanan also lost his heart and the two became nobodies.

For a brief period of time, Xaldin trains Xthanan to wield the power of darkness.