Rahkshi

Rahkshi are suits of armor created when a Kraata is immersed in Energized Protodermis.

History
Rahkshi have been employed by the Brotherhood of Makuta for over 80,000 years. Prior to their evolution, Makuta used a lengthy process which produced inferior Kraata, and by extension, inferior Rahkshi. Despite their faults, the Rahkshi were utilized in the Brotherhood's army, such as when they ambushed the League of Six Kingdoms. After the Makuta's evolution from biomechanical beings to beings of energy, they found it much easier and faster to produce higher quality Kraata.

A number of Rahkshi created have fulfilled their duties and were released from the servitude of their creator. These Rahkshi wander the islands, lacking direction. A number of these wild Rahkshi resided in Metru Nui, under the Archives, prior to the Great Cataclysm, some of which were fought and defeated by the Toa Metru. Shortly after the event, these Rahkshi were called by Teridax to act as a distraction to the Dark Hunters. These Rahkshi were obliterated by Voporak.

The Brotherhood of Makuta had employed the Rahkshi in every force they used, from defense groups to assault teams. They are used as guards on the Brotherhood island of Destral, ordered to kill and destroy any intruders. They have also been taught to recognize the Tablet of Transit, capturing and escorting any bearers. They were also utilized in most of the Brotherhood's military operations, such as when Kojol assaulted the island of Artakha.

The Rahkshi used in this raid were destroyed in an effort by the Order of Mata Nui to eliminate all beings aware of the location of Artakha.

In his effort to harass the Matoran of Mata Nui, Teridax created six Rahkshi to defeat their protectors, the Toa Nuva and obtain the Avohkii. Though the Rahkshi were potent foes, the Toa Nuva succeeded in defeating them with the assistance of the Toa of Light, Takanuva. The Toa Nuva scrapped the parts of these Rahkshi to construct Takanuva's vehicle, the Ussanui.

When Vezon landed on Destral, sent by the Order of Mata Nui, he was immediately captured by Rahkshi which took him to Makuta Tridax. The Brotherhood also sent a contingent of Rahkshi to the Southern Islands so that they could train there. The Rahkshi annihilated the local Matoran, and used the area as their practice ground. Recently, Axonn and Brutaka went there with an army of Skakdi, which they used to fight the Rahkshi. They were used extensively during an assault on Nynrah and the final battle of the war, in which they lost.

When Teridax took over the body of Mata Nui, he used his Rahkshi to terrorize the inhabitants of the universe. He sent a group to Metru Nui in order to keep the Matoran in line (and guard entrances to the Archives), and had a force invade Odina, driving the Dark Hunters out. He also sent a regiment to Artakha, deeming the ruler of the island a threat.

Mechanical Rahkshi
It is known that Zoruxx and Krall have both created Mechanical Rahkshi, whether it be for invasion purposes or for training.

The Kingdom
In The Kingdom Alternate Universe, when most of the species evacuated to Mata Nui, the Rahkshi were not allowed to come. They tried to get through to the island, and managed to kill Pohatu and Hewkii, but were eventually driven off by Tahu, Jaller, and Kopaka. 10,000 years later, Teridax managed to create for the Rahkshi shadow armor that lasted just long enough to get through the light barrier. One Rahkshi, a Panrahk, got through and was instantly killed by the Dark Hunters. This caused concern among the ruling council. When Takanuva, Tanma, and Matoro went down into Mata Nui's tunnels, they could find no sign of the Rahkshi. Right as they were about to leave, Matoro was suddenly attacked by four Rahkshi, with more coming through the barrier. Takanuva and Tanma returned to help, and the Rahkshi were defeated.

Abilities and Traits
To create a Rahkshi, two Kraata of the same power type are required, though level does not matter. One of these is put into Energized Protodermis, where it undergoes a change: from organic living matter to a non-living, inorganic shell — the Rahkshi's body. The other Kraata then crawls inside the Rahkshi and controls it, as Rahkshi suits are incapable of operating on their own. The Rahkshi amplifies the Kraata's powers, although its effectiveness still depends on the Kraata's level. Most Rahkshi channel their powers directly through the staffs that they carry; some, like heat vision and heat resistance Rahkshi, do not do so, though their staffs still aid their powers. As such, their powers are considerably weakened without their staffs. All Rahkshi also have the ability to fly.

Rahkshi are naturally destructive, often going out of their way to cause as much damage as possible. When they are acting under orders, this instinct is channeled towards one objective, making them extremely dangerous. When they are not under orders, they are much less focused, making them still dangerous, but easier to defeat. Wild Rahkshi are also very territorial, attacking anything that invades their area, even other Rahkshi.

Trivia

 * Rahkshi seem to be the most over-used villains in both BIONICLE canon and fanon.