"Picture beings with the power and the organization of the Toa, yet unfettered by their consciences or morality. That is the beauty of being a Dark Hunter."
—The Shadowed One
The charismatic leader of the Dark Hunters was referred to as The Shadowed One, since his real name was lost to the ages. He had a bodyguard named Sentrakh and Ancient formally.
The Shadowed One was responsible for the start of the ToaDark Hunter War. During the events in BIONICLE Adventures 10: Time Trap, he discovered Teridax's murderous actions against his Dark Hunters and battled him for supremacy. He was thrown into Voporak's aging shield, resulting in him aging over 3,000 years in mere moments. He survived this encounter and still existed in the time of the Toa Nuva, having sworn revenge on the Brotherhood and causing a war that had raged for at least 1,000 years and resulted in the mass deaths of Toa everywhere.
One of the core rules of being a Dark Hunters was that a Hunter was a Hunter for life, withdrawal resulted in death... or worse. The Shadowed One was aware that the Piraka had resigned from the Dark Hunter organization, and sent multiple Dark Hunters in route to Voya Nui. He also enjoyed pairing foes or very different Dark Hunters together, but whether this was for character building or his personal fun is unknown.
The Shadowed One actually intended to kill Zaktan some time ago with his eyebeam power. However, something went horribly wrong, and Zaktan was transformed into his current Protodites condition.
The Shadowed One faced a difficult decision during the invasion of Karda Nui: to either keep all of his Dark Hunters fighting against the Brotherhood of Makuta or send half of them to go after the Mask of Life, leaving the other half vulnerable to attack.