Zoids Wild Zero

In the 21st century planet Earth was rendered inhospitable to life, and people mass-migrated to Planet Zi, the natural home of metallic life forms known as Zoids. Many years later, Zi faces its end. Its inhabitants partake the journey to migrate back to Earth. Attempting to regenerate the Earth to make it hospitable, the migrants come up with a "Zi-Forming" scheme. However, the plan fails and Earth is left in its state of turmoil. Overrun by Zoids and blanked by unstable weather phenomena, the m...