Given the wordplay possible with Endgame and Game of Thrones, and the cultural event that is this weekend in both regards, my overactive imagination can’t help going all Number of the Beast via the quantum realm.
An expansive take on quantum many worlds theory is that anything that can happen as a branch of reality creating a parallel universe not only does happen, but also any fictional reality exists as an actual reality in its own universe (or presumably its own infinitely branching multiverse). Heinlein’s Number of the Beast, not IMHO his best work ever, yet intriguing enough that I read it twice, long ago, delves into that, notably by visiting Oz.
So I find myself picturing the Avengers gang going astray and landing in Westeros in the midst of the… endgame… of the Game of Thrones universe as, up to that point of departure, depicted in the TV series. Puny Mountain! Hulk smash. But perhaps I’m just easily amused.