Actor Ross Marquand, who played the Red Skull in "Avengers: Infinity War" and "Avengers: Endgame", has revealed he has spent seven or eight years pitching Marvel Studios a spin-off exploring what happened when Captain America returned the Infinity Stones after "Endgame". The idea taps into a long-standing fan desire to see the loose thread tied up, particularly the moment Steve Rogers would have had to confront Red Skull, who was left guarding the Soul Stone after being banished there in a previous film.

Speaking to Polygon during promotion for "X-Men '97", Marquand suggested the story would work best as a seven- or eight-episode animated series, with one episode devoted to Bruce Banner and Cap planning the mission and each of the six stones returned in its own episode, ending with the Soul Stone and Red Skull. He speculated the Red Skull would be freed from his "cursed" guardianship and turn hostile towards Cap, before a climactic showdown and a final episode teasing further danger. Marquand said he has had no confirmation of interest from Marvel boss Kevin Feige or Chris Evans, though elements of the stones' return could yet surface in the upcoming "Avengers: Doomsday".