Marvel did not expect "Thor: Ragnarok" to be such a huge hit, so much so that they even feared that its failure would cause the Marvel Cinematic Universe (MCU) to collapse.

This was not the case, however, as the third "Thor" movie was a blockbuster, both commercially and critically, and even went on to score a whooping 93 percent on Rotten Tomatoes. Now, Marvel and its representatives have spoken up about their worst worries regarding the movie before it premiered.

Kevin Branagh, director of the first "Thor" movie, has spoken up about how the superhero's own franchise was crucial to the survival and success of the MCU. This was because prior to Thor, there have only been two MCU Avenger superheroes who have had their own movies. These were Iron Man and Hulk, with the latter's own movies prior to "Avengers" having a poor reception.

Branagh has suggested that, had "Thor" been not as successful back then, the "Avengers" would not have gained much success, even with the arrival of "Captain America: The First Avenger" back in 2011. It seems that the deciding factor was "Thor's" reception after its premiere a few months following "Captain America."

"I am most certainly going to see Thor, and I do care about it, and I'm thrilled that they're making a third one and I love that director. ... Remember, there were only two pictures in the Marvel Universe. Iron Man, genius, the first one. Hulk hadn't worked as they'd hoped. ... And then number three, it was sink or swim before Captain America and then suddenly, oh, it was fine after that. We make Iron Man 2 and Avengers and everything's tickety-boo. But everybody who was there knows that that was an incredibly sweaty time," said Branagh.

Much of "Thor's" success is owed, apart from Branagh's direction, to Chris Hemsworth's acting, as Branagh acknowledges the actor's penchant for humor and drama. The movie ultimately carried itself while remaining an integral part of the "Avengers."