Nidhiki

Life as Toa
Nidhiki came to Metru Nui as one of the eleven Toa who fought the Kanohi Dragon, along with Toa Lhikan. Like the rest of his team, he stays as one of the city's resident Toa.

Two thousand years later, the city's leader, Turaga Dume, refused to allow the Dark Hunters to build a base in Metru Nui. The Dark Hunters attacked the city in retaliation, and hundreds of Toa (led by Lhikan) rally to the city's defense. The fighting goes on for months, with heavy casualties on both sides. Seeking to save his own skin, Nidhiki strikes a deal with the Hunters and agrees to lead the Toa into a trap. However, Lhikan finds out and sets a trap of his own. This action ends the war with the Toa as victors, and Lhikan kicks all Dark Hunters out of the city – Nidhiki along with them.

Become a Dark Hunter
With nowhere else to go, Nidhiki joins the Dark Hunters as an instructor, teaching others – including Piraka Vezok – from his experience as a Toa. Wanting to be more than a teacher, he asks to be sent on missions. He gets his wish, but to his displeasure is paired with a rather dim, brutish Hunter named Krekka. From the perspective of the Hunters' leader, the Shadowed One, this is a good partnership: Krekka can be effective if he follows Nidhiki's plans, while Nidhiki can be kept in line by Krekka's loyalty to the Hunters.

However, Nidhiki continued to want more, dreaming of being a hero again. When Roodaka came to the Hunters seeking training, he offered to reward her if she would help him escape the Hunters. Instead, she alerted the Shadowed One to Nidhiki's plans and "earned" her training by mutating him into an insectoid monster, ensuring that he could never be accepted anywhere except the Dark Hunters. (Ironically, Nidhiki was insectophobic).

Hundreds of years later, Nidhiki and Krekka were sent back to Metru Nui on a mission for Makuta. Their task was to retrieve six Great Kanoka Disks and to get Toa Lhikan out of the way - an assignment Nidhiki enjoyed, as he still held a grudge over his banishment. While the two were able to capture Lhikan, he had already chosen replacements and set them on the path to become the Toa Metru. Nidhiki blackmailed one of the Matoran, Ahkmou, into helping him get the Great Disks, but this failed as the Toa Metru were able to get to them first. Nidhiki and Krekka continued to hunt the Toa Metru until Makuta decided to face the Toa himself; in order to increase his power quickly he absorbed the two Hunters and his pet, Nivawk, into his body, killing them.