Great Cataclysm

The Great Cataclysm, otherwise referred to as The Fall by Av-Matoran, was a universal shockwave felt across the Great Spirit Robot as it crash-landed on the planetary body of Aqua Magna. This was prompted by Makuta Teridax debilitating Mata Nui's operating system in the Core Processor of Metru Nui.

Tension
Over the course of the preceding century, the unsavory agendas of both the Brotherhood of Makuta and the Dark Hunters became more clear to the Toa and the Order of Mata Nui. This period also saw a general decline across the universe, as the Brotherhood began to pay less attention to preserving order and more to their own ambition while the Dark Hunters continued to expand their criminal enterprises and earning the sympathy of dissatisfied working masses across the Matoran Universe.

Aftermath
The ramifications of the universal shockwaves had disastrous consequences throughout the domes of the Great Spirit Robot. Most notably, the Southern Continent's dome was known to have ruptured, catapulting Voya Nui and Mahri Nui to the surface of Aqua Magna and killing Turaga Jovan in the process.

To Be Added

By the time of the Great Cataclysm, the total Toa population had begun to see drastic decreases in size, with members of the species now being hunted by the Brotherhood and Dark Hunters alike as a direct consequence of the event. With Mata Nui distinctly absent and the Matoran Universe debilitated by Makuta Teridax's efforts, it became widely accepted that the Toa had failed and that alternative methods of peace-keeping should be adopted. As the Great Spirit’s health deteriorated, so did order and law on all the lands. With the Matoran Universe debilitated and the Brotherhood of Makuta now in a prime position of power, thus began the Dark Times.