Bionicle
Following the chase for the Mask of Life, the Toa Inika descended into the waters after receiving the mysterious clue "save the sunken city" from an unknown Matoran, who had saved Hahli from drowning at the cost of him dying from decompression sickness.[14] A burst of energy from the Mask of Life transformed the Toa Inika into water-breathing forms. They discovered an inhabited village of Mahri Nui that had broken off from Voya Nui and sunk a thousand years ago. The village was threatened by ancient warlords known as Barraki that had been mutated by the nearby mutagenic waters called "The Pit". The Toa, now known as Toa Mahri, faced off against the Barraki to survive. However, by the time the Toa retrieved the mask, the Great Spirit died. Realizing there was still hope, Toa Matoro rushed to the core of the universe and sacrificed his life to revive Mata Nui. In the last moments of his life, Toa Matoro used the Mask's power to teleport the Toa Mahri back to Metru Nui and allow them to breathe air again. The Great Spirit's life was saved but he still had to be awakened.