Vahki (Earth-4001)

"Surrender or run."

- The common Matoran phrase referring to the Vahki

Vahki were robotic order enforcement squads designed to protect and maintain order in Metru Nui before the Great Cataclysm.

History
The history of the Vahki is the same as their mainstream counterparts.

Description
With the ability to transform from a biped to a quadruped state, the Vahki were programmed with one directive: to preserve order and stop lawbreakers by any means necessary. Though Vahki often tried to stop the Toa Metru, they were not evil and obeyed any order they were given by Turaga Dume. They were well known, and somewhat feared and resented, for being coldly efficient and dedicated. One thing that did deter them a bit was deep water - even the Bordakh model, which were better adapted for swimming than the other kinds of Vahki.

Nuurakh
Nuurakh were the type of Vahki designed and assigned to protect and maintain order in Ta-Metru. They were the fastest of the Vahki and preferred to lie in wait of targets and then swiftly surround them in ambushes. At times when they couldn't find lawbreakers, they had been known to start fights with each other that other Vahki had to break up.

Their Staffs of Command could fill the mind of a Matoran with a single overriding directive, which they would follow until the stun wore off hours later.

Bordakh
Bordakh was the type of Vahki designed and assigned to protect and maintain order in Ga-Metru. Bordakh loved to delay the chase, loving the thrill of the pursuit. Bordakh were also the only model of Vahki designed to function underwater, although even then they tended to avoid it.

Their Staffs of Loyalty could temporarily turn Matoran into zealous supporters of order that would even help the Vahki apprehend their own friends.

Vorzakh
Vorzakh were the Vahki designed and assigned to protect and maintain order in Le-Metru. Vorzakh, much like the Zadakh, didn't have the patience for long chases. Unlike the Zadakh, the Vorzakh were lazy, just wishing the chase to be over with. They would rather just smash everything in their path until they had found whoever they were searching for.

Their Staffs of Erasing could temporarily eliminate a target's higher mental functions, leaving only their motor functions intact, although at one point, a group of Vorzakh used their staffs to destroy part of a chute in an attempt to catch Toa Metru Matau. Le-Matoran had gotten used to seeing these sorts of victims, known as "shamblers."

Keerakh
Keerakh were the Vahki assigned to protect and maintain order in Ko-Metru. Keerakh didn't even bother to chase lawbreakers, for they had an uncanny ability to deduce a target's destination and then get there first.

Their Staffs of Confusion could scramble a Matoran's sense of time and place.

Zadakh
Zadakh were the model of Vahki assigned to protect and maintain order in Po-Metru. The strongest of the Vahki, Zadakh were fearless to the point of recklessness and always eager to jump into a fight.

Their Staffs of Suggestion left a target willing to follow orders from almost anyone.

Rorzakh
Rorzakh were the Vahki designed and assigned to protect Onu-Metru. The Rorzakh were utterly relentless. They would follow their target anywhere no matter what the risk, continuing even if it meant their own destruction. According to Vakama's tale, in Metru Nui there was a story that a Rorzakh once plunged freefall into a mineshaft to catch a lawbreaker.

Their Staffs of Presence made it possible for the Vahki to see and hear whatever the affected being did, without the subject being aware.

Specialized Models
When regular Vahki cannot contain a disturbance, a bigger, specialized machine may be called in.

Kraahu
Kraahu had knowledge centers located throughout their bodies, allowing them to split apart. As a full unit, they could spray stun gas.

Kranua
Kranua could turn themselves into living sand, allowing them to capture foes quicker and confuse Rahi with randomly disappearing and reappearing.

Kralhi
Kralhi were the prototypes of Vahki, created by Nuparu as an attempt at creating law enforcement. They were discontinued after being proven to cause lawbreakers to be rendered unable to work for days. They were later driven out of the city by Vahki.

Kralhi had the ability to fire energy spheres out of their tails, which would surround a target and drain them of their energy.

Trivia

 * In BIONICLE 2: Legends of Metru Nui, the only Vahki models seen were the Zadakh and Rorzakh. Additionally, in the movie, the Vahki models wielded the Staffs of Erasing, and they held the staffs backwards.