Iron Man. As the MCU evolved, many heroes had to change to better adapt to what the studio wanted to tell, and while not all were positive changes, others were so effective that even extended the stay of some characters in the MCU for a bit longer.

Such is the case of Thor, who went from being one of the least popular of the Avengers to a favorite among fans thanks to his third solo film, Thor: Ragnarok. Directed by Avengers: Age of Ultron. Thor and Hulk reunited in Saakar, where Thor was sold as a slave and gladiator to the Grandmaster and Hulk was a successful and popular fighter in the Grandmaster’s Contest of Champions.

Related: Thor: Ragnarok Referenced Jeff Goldblum's Failed Hulk 2003 Audition

Thor: Ragnarok revealed that the Hulk hadn’t transformed back into Bruce Banner since leaving Earth, and was pretty much stuck as the Hulk by then – however, the film made an important change to the character that helped make an even bigger one in Avengers: Endgame.

Thor: Ragnarok Took A Big Step Towards Smart Hulk

Thor and Hulk sitting on a bed in Thor: Ragnarok

In Thor: Ragnarok, the Hulk suppressed Banner by avoiding anything that could calm him and reawaken Banner, and as such his speech was limited and similar to that of a toddler. Hulk eventually transformed back into Banner after a recording of Natasha awoke his human side. Although Hulk is a more primitive side of Banner and shows little signs of his human one, there is a moment during a conversation with Thor at his room in Saakar that brought out the humanity in him, even if briefly.

Annoyed by the Hulk not listening to him, Thor furiously told him that he was known as the stupid member of the Avengers, which obviously made Hulk very angry, to the point where he threw a shield at Thor that nearly decapitated him. After Thor told him that everybody on Earth hated the Hulk, they calmed down and sat down to talk again, with Thor pointing out that he can’t “go around throwing shields at people”, to which the Hulk replied with “I know, I’m sorry! I just get so angry all the time”, adding that “Hulk always angry”. Though it might seem like an irrelevant line, it’s actually proof that his human side was still present even when transformed into the Hulk, as he always talks in the third person and this time he used “I”.

Conversely, in Avengers: Infinity War, Banner tried and failed to transform into the Hulk, with the latter refusing to come out. However, in Avengers: Endgame, five years after Thanos’ death, it was revealed that Banner managed to merge himself with the Hulk, becoming what’s now known as “Smart Hulk”: Banner’s intelligence and consciousness in the Hulk’s physical appearance and strength. The aforementioned line in Thor: Ragnarok was a step towards that direction, as it showed that Banner’s human side could still be present in the body of the Hulk, and it was only a matter of experimenting a bit on how these two sides could successfully merge and make Banner/Hulk an even more important member of the original Avengers team.

Next: Why Mark Ruffalo Replaced Edward Norton As Hulk In The MCU