Mata Nui was created hundreds of thousands of years ago, by the Great Beings, to explore and observe the galaxy. He contained the Matoran Universe within his body, and created much of what existed within, among them Teridax. However, due to his neglectfulness, and Teridax's own great ambition, Teridax betrayed him and poisoned him with a virus that sent him into a deep slumber, and, ultimately, killed him (for a time). When Teridax seized control of his body and banished his soul outside of it along with the Ignika, Mata Nui was given a body and became conscious. With the knowledge of his past failures, he decided to become a true hero, one worthy of the Matoran Universe's respect.