Capcom needs to make a Marvel Superheroes 2

 Not a MVC4 but a Marvel Superheroes 2. Picture a fighting game with  60+ Marvel characters. I say + because certain characters can be "skins" for example, with Spider-Man you can also get Ben Reilly, Ben Scarlet Spider, Kaine Scarlet Spider. If they were to add Ant-Man(Lang), Yellowjacket (Pym), Goliath (Foster) can be skins, Black Widow gives you both Natasha and Yelena. With Jean Grey you can also get Rachel Summers. Boom Boom and Jubilee can be skins of the other. Baron Mordo can be a skin for Doctor Strange.

The idea is to have all the previous Marvel characters from Capcom games in addition to newcomers. (Hint: I demand a Doctor Octopus)

The premise could be a brand new Secret War with the Beyonder bringing forth everyone into a "multiversal Battleworld".  The Beyonder picks multiple characters and pits them in a Battle Royale with the winner receiving a fraction of the Beyonder's power to change reality. Examples: Doom takes the power to become the supreme ruler of Earth... Doctor Strange uses the power to undo Mephisto's meddlingnwith Spider-Man. Ben Reilly uses it to cure himself from Clone degeneration and to live a happy life with Elizabeth Tyne. Peter usesthe power to see Uncle Ben one more time, who tells Peter not to bring anyone back from the dead. Wolverine uses it to unlock all his memories. X-23 uses it to heal Gabby. Magneto creates his Mutant Utopia... 

It doesn't require too much explanation since it's a fighting game. The additions to the roster would be to complement existing characters and add some very important characters that have been skipped for some reason...

And yes, saying right from the get go that they have the Fantastic Four AT LAST is a huge selling point for me.

Then of course, Capcom can add DLC characters and stuff.