The Bohrok-Kal were six Bohrok, one from each swarm, gifted with powers far beyond those of their brothers. They were given special markings to distinguish them from the rest of the Bohrok. They were hidden in a special chamber far from the nests. If the Bahrag were ever defeated, either by an enemy or a natural force, the Bohrok-Kal would awaken. Their mission would be to find the Bahrag, free the Bahrag, and unleash the Bohrok swarms once more.
The Bohrok-Kal were a special squad of Bohrok, mutated to give them amazing powers. Their goal was to free the imprisoned Cahdok and Gahdok and unleash the Bohrok swarms once more. The Bohrok-Kal were able to combine their forms and powers like the Toa Nuva, creating two powerful Bohrok-Kal Kaita.
The Bohrok-Kal were once units of the Bohrok swarms until they were mutated by strange energies to become the ultimate Bohrok. Their silver armor and the symbols on their faceplates told the world that they were to be feared.
The six Bohrok-Kal were a special team of Bohrok with one mission: to free Cahdok and Gahdok from imprisonment. Once free, the Bohrok queens would again unleash the Bohrok swarms. The Bohrok-Kal were given unique powers and were far more dangerous than ordinary Bohrok. It would take everything the Toa Nuva had to defeat these foes.
Tahnok-Kal was the leader of the Bohrok-Kal squad.
Like the Bohrok, each of the Bohrok-Kal carried within it a krana-kal.
Tahu Nuva realized that their alliance with the Bohrok and Bohrok Va may have been a serious mistake, since the Bohrok-Kal seemed to exert some kind of influence over them.
Bohrok-Kal were described as insect-like.
The Bahrag created the Bohrok-Kal by mutating six Bohrok and their Krana. Exactly how the Bohrok-Kal were created was never determined, but some believed that the Bahrag discovered a way to distill energy from a mutagenic substance such as Visorak venom and then used it to bathe the Bohrok and their Krana, resulting in mutations.
The Bohrok-Kal challenged the Toa Nuva in an effort to free the Bahrag and unleash the Bohrok swarms on Mata Nui a second time. They were defeated by the Toa Nuva and were not a threat since that time.
Analogously to regular Bohrok, each Bohrok-Kal was controlled by a Krana-Kal contained within its headplate. However, each Bohrok-Kal had a power which was vastly different from that of a normal Bohrok. Their Krana-Kal provided additional power, were capable of communicating with other species, and were not mentally linked to the Bahrag. Like Bohrok, each carried two shields through which they focused their powers.
The Bohrok-Kal tended to be arrogant and cruel. In contrast to the Bohrok, which did not harm living beings unless they directly interfered with their mission, the Bohrok-Kal would willingly attack Toa, Matoran, and even other members of the Bohrok swarms.
The creation of the Bohrok-Kal was probably pre-programmed into the Bahrag by the Great Beings.
The Bahrag mutated six Bohrok to create the Bohrok-Kal.[11, 12] They were mutated with a combination of protodermis and energies unique to the Bahrag. The Krana-Kal were mutated from regular krana along with the rest of the Bohrok-Kal's bodies.