"Shadow Stealer"

Not many hard facts are known about Shadow Stealer, though he has been known to attack Toa and Dark Hunters alike. Some legends say he was a hero before even the Toa existed (he was once a member of the Hand of Artakha), and became jealous when Toa became Mata Nui's champions. "The Shadowed One" originally sent him to the ends of the earth to complete a mission of several years, but Shadow Stealer finished in days and has been working his way back ever since, fighting Toa and Dark Hunters on the way. The Shadowed One seems to plan to challenge him once he returns. Shadow Stealer can absorb shadows and convert them to energy, and he can teleport using shadows as exit and entry points (though there is apparently a limit to how far he can go). These powers make him a threat to the Brotherhood of Makuta - there's even a rumor that the Brotherhood tried to hire a Hunter to eliminate Shadow Stealer!