Reysa lived on an island in the Matoran Universe until being sent to Karzahni to be fixed. However, the ruler failed to do so properly, and sent him to the Southern Continent. During the Great Cataclysm, Reysa was on the chunk of land that was blasted onto the surface, later known as Voya Nui. Some time later, he and a group of other Matoran had settled in a city that was built on the coast. The chunk of land the city was built on sank into the ocean; the inhabitants named the city "Mahri Nui."
While waiting for the Hydruka to harvest Air Weed, he heard a noise coming from below and started to investigate. However, he had stayed outside too long, and was dragged into the abyss below Mahri Nui and killed by a tentacled Rahi shortly before the KanohiIgnika appeared.