Vahi

The Kanohi Vahi was the Great Mask of Time, made from the six Great Disks and was one of the most powerful Kanohi in existence, at the level of the Ignika. The mask was wanted by several organizations, the known ones being the Brotherhood of Makuta, the Dark Hunters, and the Order of Mata Nui. However, unlike the former two the Order of Mata Nui was happy with the Vahi being kept by Turaga Vakama.

Creation of the Vahi
The Makuta under the disguise of Turaga Dume, asked Vakama shortly before he became a Toa, to make one. He wanted to use it to speed up the process of erasing the Matoran's memory with the Matoran Pods. Vakama could not create the Vahi as a Matoran, but he did create the mask after becoming a Toa Metru, during the events of BIONICLE Adventures 4: Legends of Metru Nui, melding together all six Great Disks.

History
Shortly after creating the Vahi, Vakama attempted to use it against Makuta, but he only managed to slow down himself and Makuta. During the battle, the Vahi fell into the Silver Sea.`

In BIONICLE Adventures 10: Time Trap, Vakama went back to retrieve the mask from the sea. Although originally gold, it had turned orange from exposure to the sea. When it was stolen by "The Shadowed One" and Voporak, Vakama and Makuta teamed up to get it back. When Vakama recovered it, Makuta attempted to get it for himself. Vakama discovered that if the Vahi was destroyed, time itself would halt, and he threatened Makuta by saying he would do it. Makuta teleported Vakama to Mata Nui and Vakama kept it hidden during his next 1,000 years on Mata Nui.

After the Toa Mata came and transformed into Toa Nuva, Vakama (now a Turaga), gave the Vahi to Tahu Nuva who used it to delay the Bohrok-Kal's attempt to free the Bahrag. It almost overwhelmed Tahu and he later gave it back to Turaga Vakama, who kept it.

Trivia

 * Voporak was a being who was made by the Brotherhood of Makuta to detect uses of the Vahi. He and "Ancient" were making their way to the Bahrag's chamber during the events of the 2006 storyline, tracing Tahu's use of the Vahi.
 * Theoretically, it could be used on Mata Nui to slow down time around him slowing his death, giving the Toa Mahri more time to complete their task. But this is unlikely, as the Vahi uses a lot of energy from a Toa. But possibly they could convince Makuta to do it, because he would die if he didn't. But at this point,this theory is no longer required.

Set Information
The orange Vahi was originally to be included with the BIONICLE: Legends of Mata Nui PC game in 2001. However due the game being canceled, the Vahi remained absent, until 2003 when it was given away at select LEGOLand locations, and select Walgreens with a purchase of one BIONICLE set.

The gold Vahi, called the movie edition, was later available at Target, included with specially marked Vahki. The gold version could also be found in large tubs that were sold at Toys"R"Us.