Infinity War in your campaign (Spoilers)

[Imaculata]

...now in a role playing game you need multiple pathways not just one, because unlike in a movie where the characters always do what the author wants, player characters are unpredictable, you need to allow leeway to have multiple ways to beat the bad guy.

Funny enough, I didn't actually come up with a way for the players to beat the big bad in my campaign. I simply set up a terrifying foe, and gradually built him/it up to be a truly powerful cosmic threat. But what I did do, is set up some clear limitations regarding what the big bad can and cannot do.

As the story progressed, it was the players themselves who came up with some ideas of how to possibly deal with the big bad. It was only then that I started preparations to allow the story to run with their ideas, and incorporate them into the greater narrative.

Its like planning towards Avengers Infinity War part 2, without knowing how the story is going to end exactly, apart from it probably being a big battle.