I liked this movie when it was called Mystery Men (1999)

It's NOTHING like mystery men. It's just a completely different movie, the story is totally different. It's not even conceptually similar in any way, shape or form.
"Super Villain destroys the Super Hero and feels let down."
This is not what happens in Mystery Men at all. Did you even watch the movie?
But the again, if this is from IMDB, I guess you may never see this?

I agree with the second poster that this movie is nothing like Mystery Men. The two are almost polar opposite.

And I suppose it’s debatable, but in Mystery Men, I always got the feeling that Casanova Frankenstein only felt let down because he wanted to kill the hero (Captain Amazing) himself in front of all the other villains. He was mad that the opportunity was taken from him and no one witnessed the great show he had planned.