You Nitwit! Heroes are Extinct!!(2003)

Tennen! Zetsumetsu Hero!!

A hero from a distant star arrives on Earth to pit his strength against Earth’s famous superheroes! Only problem is… Earth doesn’t really have any superheroes. Growing up watching superhero TV shows from Earth – think Power Rangers of Ultraman, our fearless hero decides to amass an army on his home planet and invade Earth in the ultimate test of strength. Only the invasion starts and no one comes to stop him… What is an alien on Earth supposed to do with an entire army and no one to fight?!?

(Source: Digital Manga Publishing)