"Shadow Stealer"

"Shadow Stealer" was a former member of the Hand of Artakha and later a Dark Hunter.

History
Some legends say he was a hero even before the Toa existed (he was once a member of the Hand of Artakha), and became jealous when the Toa became Mata Nui's champions.

The Shadowed One originally sent him to the ends of the Matoran Universe to complete a mission of several years, but "Shadow Stealer" finished in days and then slowly made his way back, fighting Toa and Dark Hunters on the way. "The Shadowed One" seemed to plan to challenge him once he returned. It is unknown if he returned before Teridax's death and if he and "The Shadowed One" clashed.

Abilities and Traits
"Shadow Stealer" could absorb shadow and convert it to energy. He could also teleport using shadows as exit and entry points.