OmniverseClassicEditionSourcebook

This is an older game system - the old TSR 'Classic' Marvel Superheroes game - the game mechanics are a bit cruder, and the layout isn't as spiffy as M&M's but a lot of material was published, making it one of the most comprehensive Marvel Universe series ever put out.  It's also one of the only versions to quantify entity-level beings as high as Eternity and the Beyonder.

A lot of the official books are still available on line - notably at the Classic Marvel Forever site.

I've compiled all my own entries into a single volume - so it's a big file - nearly a thousand pages, so I hope it's not too big for the site, but it might take a minute to download.
(Download button is on the right)

And here's the shameless plug for the latest novels: