Go! Go! Loser Ranger! 6 (manga)

Thirteen years ago, an evil army of mysterious alien monsters invaded the Earth, but the great protectors of mankind-the Divine Dragon Rangers-rose up to stop them! To this day, the fate of the Earth hangs in the balance as the fierce struggle continues to unfold! In truth, the evil aliens were subjugated within the first year, and they've now become nothing more than clowns forced to act out their continuous defeat every week for the entertainment of the masses. But one of the aliens has had enough. Something has to change! He'll rebel against the strongest might of the Dragon Rangers and destroy them all from the inside!