Thor: Ragnarok is pegged to be one of the most important films in the Marvel Cinematic Universe. This is the film that is supposed to have the strongest ties to the formerly titled Avengers: Infinity War 1 & 2. But Thor has to deal with Ragnarok a.k.a. The Twilight of the Gods. It has always been known that Hela would be the main antagonist. But it was revealed at San Diego Comic-Con 2016 that she would not be alone. Two more villains were revealed and that was the Fenris Wolf and Surtur. Surtur is very important as Ragnarok has been depicted in the comics and Surtur is usually the cause of these events.
Though nothing was released the public, audiences inside of Marvel's conference revealed that two pieces of concept art were shown. Thor (with a shorter haircut) will be facing off with the Fenris Wolf while Hulk will be squaring off with Surtur. Since Ragnarok is supposed to be the end of the Asgardian gods, it is no surprise that they would not take this lying down. Though exactly how the Hulk enters the fray is still a mystery, it is no surprise that he is in the movie. Thor will definitely need help in dealing with these events as he cannot call on the rest of the Avengers because despite them being warriors, they are still mortals. Though Hulk is a mortal, he is much more than that, sometimes equated to rage incarnate.
Thor and Hulk were excluded from the events of Captain America: Civil War because they are the two most powerful characters in the Marvel Cinematic Universe introduced. So where would they go? Only to an extinction level event brings the two together along with the Asgardian forces. Since Hulk cannot have a solo movie, his villains are trickier to introduce. So what's the next best thing? Have him in Thor's movie where it is filled with gods, demons and monsters. We've already seen him square off against Thor in The Avengers, so it's time to introduce some other immortal foes for Hulk to smash:
Though the movie seems to be filled with villains, who knows how much of an actual role Surtur and the Fenris Wolf have? Hela still looks to be the driving force and the main antagonist. Cate Blanchett is playing the character and there is no way they are going to shaft the Academy Award-winning actress. More and more details about Thor: Ragnarok are bound to come out in the months coming out. The movie has only been filming for about a week. Either way, the movie is shaping up to be an exciting movie. Is this the end of the Asgardians? We will see.