Arrival on OkotoEdit
The Protectors performed a ritual involving the Prophecy of Heroes in order to summon the Toa. Onua was one of the warriors summoned, and crashed into the Earth region of Okoto. He met Korgot and several earth Okotans, without any knowledge of who he was and what is purpose was. Korgot then briefed him on his mission to save Okoto from evil, and that started by retrieving the Golden Mask of Earth. Onua retrieved the mask in the earth Region's underground caves and defended Korgot from a swarm of Skull Spiders. Onua then received weird visions involving Ekimu. Korgot told him that he must meet the other Toa and awaken Ekimu.
Battle for the Ancient City Edit
Onua then proceeded to meet the other Toa, who all were on board with the same goal of awakening Ekimu. Kopaka and Tahu intially clashed over leadership, but it was broken up and Onua told them not to fight. They then advanced in the direction of the Ancient City. However, the Lord of Skull Spiders had blocked their entrance to the city by standing on the bridge, and the Toa united their powers in order to knock the infamous creature off. They then arrived at the ancient city, which was overrun by many undead threats. However, the Toa managed to overcome these trials and finally awaken the mask maker. However, they still needed to retrieve the Mask of Creation, Ekimu's mask, from Kulta, the Skull Grinder.
The Toa were immediately stunned in the battle with Kulta by his powerful blows. Along with the rest of the Toa, Onua was knocked to the ground, sans mask, by Kulta. Ekimu then created his own shield and hammer, defeating Kulta himself. Onua's mask was later repaired after being broken in the battle with Kulta.
Uniting with Terak Edit
Briefed by Ekimu on their next mission, Onua and the Toa found they must unite with the Elemental Creatures to find the Golden Masks of Unity and find the Mask of Control, Makuta's mask. Onua found Terak in an Earth Temple deep underground, after chasing him through subterranean caves. However, Onua learnt that he must use the elements and work with Terak to create an earth bridge so he can get across the wide crack seperating them, and finally found his own Golden Unity Mask of Earth, which gave him the ability to physically join with Terak.
The Toa reunited once more after finding their creatures and their golden masks, this time with a goal to reach the Labyrinth, the Mask of Control's location. Onua and the Toa overcame the several obstacles placed inside the Labyrinth, escaping a close death. However, Pohatu struggled to unite with Ketar, which allowed Umarak to steal Ketar and the Mask of Control. Pohatu fought Umarak and had to choose between Mask of Control or Ketar's life, and Pohatu chose the latter. Umarak escaped with the mask, leaving the Toa to regroup.
The Shadow Realm Edit
Onua and the Toa were soon attacked by a new threat; the Shadow Horde. They were able to find a weakness to them and proceed to fight them off, only to realize that it was a mere distraction. The Toa, now joined by a newly upgraded Ekimu, chase down Umarak, who had found the several fragments that can be used to open the Shadow Realm 's portal. The Toa faced off against Umarak, resulting only in Gali getting sucked into the Shadow Realm.
Onua then joined the Toa in an attempt to defeat Umarak, but they soon fail due to his strength. Umarak then got vaporized from the pressure entering the Shadow Realm, destroying the Mask of Control in the process. Gali escapes and tells the Toa that they must unite to take down Makuta. Makuta attempts to escape from the portal, but the Toa soon used up all of their elemental powers to seal Makuta back in, immediately resulting in them returning to the stars, only to return when Okoto needs them the most.