Karzahni (Being)

Karzahni was one of the first beings, who ruled over the realm of Karzanhi. He and his brother Artakha were two of the first creations of the Great Beings, and each was given a domain to rule over. Originally, Matoran were sent to Karzahni in order to be repaired - but Karzahni never really did a good job. He tried to make up for it by supplying the Matoran with weapons to defend themselves, but eventually Matoran stopped being sent to him. Over time, his and Artakha's realms passed into legend, with the myths saying that bad or lazy Matoran were sent to him not for repair, but for punishment.

Karzahni has an ancient appearance, with ebon and gold colored bladed armor and a mask that is seemingly made of 3 or 4 older masks patched together. He speaks in whispers and has deep hollow black eyes. He carries a burning chain and his gauntlets crackle with energy.

His Kanohi Mask can make himself and others experience alternate or possible futures, usually bad ones (for instance, Jaller saw the devastation which would have come to pass if Takua had never become Toa Takanuva). When Matoran enter his domain they can't escape and he has them abandon their old masks as a way of making them abandon their old identities, and he uses his alternate-future power to make them lose hope. Those who disobey get turned to stone.

Until recently, he did not even know of the Makuta or Mata Nui. At first, he didn't believe the tales, but then through his own mask power he saw that the universe would cease to be if Mata Nui died. Now that he knows what exists outside his kingdom, he aims to take control before Mata Nui wakes up.

According to the Order of Mata Nui, after Jaller and his team departed from the realm, Karzahni began organizing his Matoran into an army and training them. His reason for doing this is currently unclear, but it is hinted that he intends to fight Makuta with his army of twisted Matoran.

Karzahni in The Pit
When Karzahni goes down to The Pit he will be mutated like the Barraki, the Toa Mahri, etc.