Even as their reached it's technological peak, however the Chozo felt their spirituallity wane.Their culture was steeped in prophecy and lore, and they foresaw the decline of the Chozo with the rise of evil.Horrfied by the increasing violence in the universe, they beagn to withdraw into themselves, forgoing technology in favor of simplicity. Tallon IV was one of several refuges they built-a colony bereft of technology, built of natural materials and wedded to the land and it's creatures.

The years passed, and in time a great meteor crashed into Tallon IV, sending a massive spume of matter into the atmposphere and impreagnating the land with a cancerous element known as Phazon. This element immediatly sank into the earth and water, poisoning life wherever it bloomed. Most plants and animals died, while others mutated into hideous forms.

The Chozo called upon all of thier knowledge and technology to control the power of the Phazon, but the were doomed to fail.All they could do was build a temple over the crater at the impact site, seperate the Phazon core, and seal it away. Beliving that someday a savior would return to the planet, the Chozo left for an unkown destination, leaving behind but engraved accounts of thier time on Tallon IV.