The Toa Inika/Toa Mahri were the original six Matoran who appeared in the Mata Nui Online Game turned into Toa through energy from the Red Star when the Toa Nuva were enslaved by the Piraka. These Matoran were Jaller, Hahli, Kongu, Matoro, Hewkii, and Nuparu. All six had electricity powers interlaced with their elemental powers, but were mutated by the Kanohi Ignika to adapt to water.
As Toa Inika, they battled the evil Piraka for control over the Mask of Life, while also searching for the Toa Nuva, who had gone missing here. They teamed up with the Voya Nui Resistance Team, led by Garan, and consisting of Balta, Dalu, Kazi, Piruk, and Velika. They were also aided by Axonn, who was a member of the Order of Mata Nui. They eventually battled against Vezon and Fenrakk/Kardas, and Kongu used his Mask of Telepathy to read the Mask's mind, learning that the Mask wanted Matoro as its new guardian. After Jaller froze Vezon and Kardas, Matoro took the Mask off of Vezon. To his own surprise, it came off right when he touched it. After the Mask of Life flew into the sea, Axonn opened a secret tunnel so they could go down into the Pit and find the mask. The Voya Nui Resistance Team also rescued the Toa Nuva.
As Toa Mahri, they were branded as allies of the Barraki by the Mahri Nui Matoran, and most of the Mahri were captured by the Barraki and Matoro was imprisoned by Hydraxon, but later freed by Teridax, who had taken control over a Maxilos robot. The Toa Mahri later escaped with the help of a Krahna Crab and stole some Cordak Blasters from the Barraki. They were named the protectors of Mahri Nui by Defilak, the city's leader. They battled the Barraki and Hydraxon (who was working against both sides), and eventually, they battled the Piraka, who were now mutated into fish-like beings. They later destroyed the Cord connecting Voya Nui to Mahri, but not before putting the Matoran in the caves of Voya Nui for protection. Mahri Nui was destroyed in the process. After Mata Nui died, Matoro continued on to the Karda Nui, the core of the Matoran Universe while the others held off the Barraki. Matoro gave his life to don the Ignika and save Mata Nui's life, sending the Toa Mahri back to Metru Nui just as Jaller was preparing to do a Nova Blast. After Jaller powered down his energy, they learned of Matoro's fate from Turaga Vakama. The became the protectors of Metru Nui in the Toa Nuva's absence (they were in Karda Nui).
During Teridax's reign the Toa Mahri were chosen to do an espionage mission on the island Zakaz, home of the Skakdi, who created a powerful gold-skinned fusion. The Mahri were hypnotized by the creature and relished in following the fusion's command. On Spherus Magna, Kopaka learned of this, and Gaaki gathered her team to rescue the Mahri.