The Deathcula are a race of humanoid creatures that have invaded Earth's Solar System. They have advanced technology, allowing them to terrorize man's homeworlds. Whenever they take a experience of getting killed, their cell walls react to turn their bodies (bone and all) into black powder.
They had invaded the solar system 15 years before the series took place. Their goal was to dominate the the homeworlds of man, but their plans were foiled by the sacrifice of an ace fighter pilot who himself was the main protagonist' father. Years later, the Deathcula return to the system to get revenge against the Earth Federation Government.