Obviously, you can’t reunite the various heroes of the Marvel universe for a simple fight against plain old Doctor Doom. With a lineup of heroes like these, you need something truly threatening and world ending to bring them all together. In the original Ultimate Alliance, it was Doom uniting various villains to take Odin’s power. Ultimate Alliance 2 showed the heroes divided over superhero registration. The main Avengers comic has two big arcs that would be perfect for a third Ultimate Alliance title. Infinity has the Earth’s Mightiest Heroes fending off an attack from the Builders, the universe’s oldest race, and later on the Mad Titan Thanos. The second arc is Secret Wars, due this summer.
Right now in the Marvel comics, there’s a massive end of the world event called an “incursion”. These incursions have led to several Marvel universes being destroyed, and everything is leading up to the various characters in all the many remaining universes doing battle. Iron Man’s New Avengers Illuminati have been devoted to stopping the incursions at the cost of destroying many universes. Captain America found out about their plan and has since put his time to hunting down the scattered members of the Illuminati with the SHIELD Avengers. The short first act of the game can be in medias res, with the Avengers fighting various multiverse versions of themselves. Then, before fighting the game’s villain, the story rewinds to show us how we got to this point. How did our heroes get like this? What’s going on? Is this truly the end of everything?