The main conceit of the Last Masterless Earth is flipping the overall optimistic premise but overall keeping the heroic call to action of universes like ME-1. In this universe many Marvel heroes existed and may have saved the world from this evil alien horde, or this AI uprising, but ultimately humans destroy themselves in a nuclear flustercluck. Some people seek to bring society back together, some just look at societal eradication as an excuse to be Vikings, and others just can't handle stupid people anymore and want to be left alone. However, like all of my unis, the heroic call to action remains. In short, even if Governments, elected leaders, even legit superheroes failed to save the world, it doesn't give you a pass to give up too.
Currently, I leaning on the Protagonist (often called Lone Wanderer, Fixer, or some myriad of expletives) will be me, as a firm character cap from the ME-1, ME-2, etc incarnations. In contrast to the most optimistic versions of me, this version behaves most like Knight Owl's The Nemesis, in that he doesn't aspire to continually enhance his virtues and overcome his vices. He no longer sees the point in aspiring to be better, focusing his effort on survival, and on occasion boiling about how his species could have been so stupid and cruel to basically kill themselves.
Full body look at the Lone Wanderer
I'm debating on incorporating this mask if I were to commission this design at some point.
I haven't put much of any thought into who this villain is, or any details about is villainy, other than he's meant to be evil enough to force the protagonist out of his resignation from the human race. I also in general want him to be antithetical to him in personality, so while the protagonist is gruff and solitary, the antagonist, despite his evilness, is more outgoing, and oddly charming in his way. Not entirely unlike the Joker.
While this universe is meant to generally be more "realistic" Marvel heroes will exist, until their inevitable demise when the nuclear fallout happens. I'm still not sure which heroes I want to be a thing, and if any might live, but currently I know Captain America will exist, and I think it's best if none are alive.
The Sentinel of Liberty: Captain America has died along with all the other heroes, but his shield is out there, waiting to be claimed by another Vanguard for the American Dream.