"Subterranean"

Subterranean was once an Onu-Matoran on Metru Nui. Many centuries ago, when the Toa/Dark Hunter War was still raging on, he was helping to build a new section of the Archives under Ga-Metru when the tunnel ceiling collapsed. What exactly happened to the Matoran is shrouded in mystery, but it is possible that there were mutagenic chemicals in a Ga-Metru laboratory above the dig site, which poured all of its contents onto him when it caved in and mutated him into his current state.

When he finally emerged from the rubble, his new form terrified his friends. Shocked, he left the city with the Dark Hunters and since then, he served as a Dark Hunter. Unfortunately, the accident created a major side effect: It enhanced Subterranean's hearing to a point when all the slightest sound will be painful to him, and due to that reason, he is equipped with new armor which would dampen the sound.

Subterranean has the power to disassemble anything he touches. He can temporarily immobilize his opponents with a mere glance. He is currently active, as "The Shadowed One" dispatched him on a mission to discuss alliance with a group of Frostelus, on the theory that he is one of the few beings uglier than they are.