Secret wars is about a cosmic entity called the Beyonder who observes the Marvel universe. The being took interests in the superheroes of Earth and their abilities. This being teleports both heroes and supervillains and put them against each other on a planet it created .This place has alien weapons and technology. The Beyonder then makes its presence known to them and tells them to slay each other and whoever wins can have anything they want.
I thing a secret war movie would make for great Trilogy. It could be the lord of the rings for marvel.