Viokah is a large, big island connected to what Matoran call, "Gastovine", a rather small islet that jutts out of Viokah, on a huge stone path known as the Berdo Cliff. When the Matoran were evacuated from the place, they fled to Gastovine, when Viokah subsided and sunk into the deep waters of the Zuax Ocean. Later, in a whole millenia, a Great Spirit, known as Toaga Nui, emerged from the sea, from when he was originally created by the Great Beings. After the Matoran came back to their island home of Viokah, Gastovine became deserted and was left to turn into a grotty wasteland.
Viokah is now currently haunted by Makuta Joder, an evil, shadowy being, known for his horrid ability to poison Toaga Nui, with his Mask of Sleep, allowing him to fall into a deep slumber. The Matoran of Viokah are fighting against Joder, only to be poisoned or more or less fall into a dark slumber.
The only Toa that remain are the eight Toa Vahi, the survivours of the event that happened when a wave of Energized Protoderis came splashing out of a bay, known as Spartax Cove, hitting the Kanohi Vahi, causing a radio-active shield around Weron, Garad, Kaukace, Saurola, Darone, Tikon, Aftonu and Xiadon, six Matoran, transforming them into the Toa Vahi.
They are currently fighting Makuta Joder, with their help of their Turaga of Gravity, Turaga Hagon.