"And there came a day, a day unlike any other, when Earth's mightiest heroes and heroines found themselves united against a common threat. On that day, the Avengers were born—to fight the foes no single super hero could withstand! Through the years, their roster has prospered, changing many times, but their glory has never been denied! Heed the call, then—for now, the Avengers Assemble!"
—Prologue from The Avengers used in the 1970s
A Random Encounter Chart The Marvel Way The "Big Guns" of The Avengers 1d200
But their glory has never been denied!
There are times when you need to bring the world to a world Earth shattering stand still! A time when the simple monsters just won't do. The above chart are the worst of the worst that the Marvel universe has to offer.
There are repeats because often times a vile villain will plague a group over & over. There are myriad of alternative versions of various characters feel free to alter yours. There have been more times when the Avengers have mettled in affairs of a cosmic nature then,I have hair on my head. From the Krovac saga to the Infinity Gauntlet they've been to the back of beyond as well as hell. So given this fact there is every reason that they might crop up from time to time in a wide variety of campaigns. Given the history of characters like Thor or the Black Knight it wouldn't unconventional to see them appearing in a fantasy table top game as NPCs even Conan did so in a Thor What if issue.Look at this point balance or anything remotely resembling it out the window. Given the nature of Mutant Future there is every reason that a wide variety of post apocalyptic universes might be open to an Avengers visit. Villains like Radioactive Man & the various mutant menaces certainly fit the bill.Then there's Carcosa which might well be a Mythos lost world itself. Given the storyline with items like Atlantis Attacks, the Serpent Crown, & other Marvel mythos issues a visit to Carcosa is not out of question.Those heroes surviving is another story though. The fact is that the various Marvel Super Heroes modules make excellent jump off points for PCs to step head first into the storyline & replace the heroes. Thor dies, Cap goes down, etc. its happened plenty of times so why not let the players have the spotlight. Come on there have been a few times when DMs in need have used high level D&D or AD&D players as super heroes
When it comes to truly confronting evil on its own cosmic terms there's only one old school game that has a great deal of the information
Marvel Super Heroes had a great book that went through the complete roster of heroes, vile villains, & complete Avengers nutcases
They even did a complete update in the form of the