Sentrakh

Sentrakh is "The Shadowed One"'s bodyguard, has the powers of illusion, darkness, molecular transmutation, and mind wipe, as well as dematerialization Rhotuka. He is silent, unwaveringly loyal, and will gladly punish anyone who dares to threaten his master. He is described as "unliving" because he cannot live or die as the Matoran see life and death.

Sentrakh cannot remember who he is, what his past is, or how he got his powers, and neither do any of the other Dark Hunters, except for the one responsible for Sentrakh's current state: "The Shadowed One". The Shadowed One used him in an experiment to make Dark Hunters that were more loyal and obedient. He succeeded, with the neither-dead-nor-alive state being a useful side effect of the experiment, but the process destroyed Sentrakh's memory, so The Shadowed One had to completely re-teach him absolutely everything (which is why he doesn't do it to all of the Dark Hunters).

In the past, The Shadowed One used Sentrakh to punish Dark Hunters which failed in their tasks. It is said that the isle of the Dark Hunters is haunted by the ghosts of those victims.

Sentrakh was defeated in battle by Vakama, but he still exists, and is currently on the Dark Hunters team looking for the Piraka.

Trivia

 * Sentrakh could be built as a combiner with Sidorak and Keetongu.