2005 - Web of Shadows

Upon the Toa Metru's return to Metru Nui, they found the city in ruins. In their absence, vicious spider-like Rahi called Visorak had overrun the city by creating poisonous webs and mutating various other Rahi while holding the sleeping Matoran captive. 

Under the command of their king, Sidorak, and his viceroy, the Vortixx Roodaka, the spiders captured and mutated the Toa into half-Toa, half-Rahi creatures nicknamed "Toa Hordika", before being rescued by the Rahaga; six small beings once Toa themselves, who explained that if the Toa wished to be changed back, they must seek the legendary Keetongu; a Rahi said to be an expert with poisons and antidotes. 

Putting their own problems aside, the Toa retrieved the Kanohi Mask of Light and built airships to transport the Matoran out of the Metru Nui. However, a guilt-ridden Vakama succumbed to his Rahi impulses and betrayed his fellow Toa by joining Sidorak and Roodaka, who made him leader of the Visorak hordes after kidnapping five of the Rahaga. Unknown to Sidorak, Roodaka had plans of her own to overthrow the horde King and accede all six Toa Hordika to rule the Visorak hordes for her, however, the treacherous Vortixx had yet even more schemes...

The remaining Toa and Rahaga changed priorities and searched for Keetongu. Finding the Rahi in Ko-Metru, the group enlisted his help and joined him in a battle against the Visorak at the Coliseum. During the conflict, Roodaka abandoned Sidorak in a fight against Keetongu, leaving the horde king to die at the hands of the Rahi, while Matau attempted to convince Vakama to re-join his team-mates by making him remember his destiny of rescuing the Matoran. 

Roodaka confronted the Toa Hordika and demanded their elemental powers. They fired their Rhotuka spinner weapons at her, but the action had little effect. After dispersing the Visorak, a rejuvenated Vakama also fired a spinner at her. This knocked Roodaka unconscious and unknowingly released Teridax from his protodermis prison that she had been carrying a shard of in her armor, before the Makuta teleported her away to safety.

After the battle, Keetongu restored the Toa Hordika back into their original forms so they could carry out the Great Rescue. The Toa Metru bided farewell to the Rahi and the Rahaga and set sail with the Matoran-loaded airships to the island above Metru Nui. 

On the voyage, the Toa noticed Teridax's empty protodermis prison cell and feared his return. Still willing to reclaim the Mask of Time, Vakama retrieved the Vahi from the protodermis sea during a battle between the Makuta and The Shadowed One; leader of the Dark Hunters. After, Vakama blackmailed the Makuta into giving the Matoran one year of peace on the tropical island by threatening to break the mask if Teridax broke his word. He agreed, and Vakama travelled on with his fellow Toa. 

Once ashore on the island, the Toa Metru sacrificed their powers to awaken the Matoran. Now Turaga, they christened the island "Mata Nui" after the Great Spirit and directed the amnesiac Matoran to building new homes, knowing the Makuta would return and that new prophesied Toa would arrive to fight him.