Great Monster War of Earth

The Great Monster War of Earth is an event that occur prior to the events of Monster Kid. It was a conflict between Zero and an ancient civilzation as well as an alien race called the Blight.

Pre-Monster Kid
Millions of years ago during the are of an ancient civilization, Zero arrived on Earth and cause great destruction while unleashing an army of monsters called Solar Beasts to conquer the entire planet as well as the universe.