|Location||Matoran Universe, Under Metru Nui|
The Core Processor was a large network of mechanics that served as the 'brain' of the Mata Nui Robot.
The Core Processor was designed by the Great Beings and built into the Matoran Universe prior to The Shattering of Spherus Magna. Two Glatorian guards we put in place to monitor and maintain the machinery while Mata Nui resided in it.
However, as the Great Cataclysm occurred, Mata Nui's consciousness was separated from the machinery and the system was put on standby.
It wasn't until 1,000 years later when Toa Mahri Matoro sacrificed himself for Mata Nui to return to the Core Processor. However, Makuta Teridax managed to beat Mata Nui to it and his consciousness was later awakened by the Toa Nuva.
Some time later, the Toa Hagah were tasked with killing Teridax and were sent to track him down with the help of the now extremely mutated Zaktan. The team arrived on Metru-Nui and began to descend into the Coliseum, where they came across a wall that stated something about 'Bara Magna', which was the only word any of them could translate. The wall was then magnetized and the Toa were left to be victim to a flow of Molten Protodermis. Luckily, they were saved by Makuta Miserix who accompanied them to the central part of the Core Processor. The team then came across the bodies of the two Glatorian Guards and two portals. From the first portal emerged Helryx and Keetongu and from the other emerged Axonn and Brutaka. This grabbed the attention of Teridax, who shattered Zaktan’s container, gave the Toa Hagah false memories of defeating Teridax and sent them off, teleported Axonn, Brutaka and Keetongu to parts of the Southern Island chain, implanted Miserix into an image on the chamber wall and kept Helryx as his servant to replace the two Glatorian he had killed.
However, some time later, several Matoran, Tuyet, and Lewa; who was being posessed by Tren Krom, arrived to free her. Tren Krom then started to utilize a message he was going to send to Mata Nui, the group met Axonn and Brutaka. They began to discuss the fate of the Matoran universe. Part way through Tuyet stopped listening and started to listen to Tren Krom's message. A conflict soon arose with two sides of an argument. Tuyet sided with Brutaka and Tren Krom, who insisted that the Matoran universe had to live while Helryx sided with Axonn and Makuta Miserix, who insisted that the Matoran Universe had to be destroyed.
Before any damage could be done to the machinery, Artakha appeared and put an end to the conflict and restored Lewa to his original body. However, this attracted the attention of Teridax who teleported the group into orbit around Aqua Magna in an attempt to kill them. They escaped and made it to Bota Magna before Teridax landed on Bara Magna.
After a battle on Bara Magna, Bota Magna collided with Teridax's head. This destroyed the Core Processor and killed him.