We've had a decade to grow accustomed to the Marvel Cinematic Universe. It has brought us a wide variety of characters, each one with a unique story. After the climactic events of Avengers: Infinity War, it's likely we'll be seeing a few characters disappear from the MCU, partly because certain actors won't be renewing their contracts and partly because their stories will end completely, making room for new heroes in the spotlight. With that in mind, we thought it appropriate to take a look back at some of the characters we've seen so far to see how well their stories have been told.

We want to see if these characters have changed since their first appearance, or if they seemed to be in some sort of narrative stasis. Obviously, since a few of these characters are still quite new to the franchise, we'll be taking screen time into account. You'll find that while some characters develop quite well without requiring that much screen time, others have their screen time wasted on more meaningless things. It speaks to how badly some of these characters need a film of their own. With that in mind, in no particular order, here are the eight best character evolutions and the seven worst.

15 BEST: CAPTAIN AMERICA

The most obvious change Steve Rogers has undergone was from that young skinny boy to the bulky supersoldier who seems to hold his own against gods, aliens and from the looks of it, mad titans. Having fought countless battles, some against those he thought were friends and allies, Cap has also turned from that relatively naive soldier to a battle-hardened, somewhat distrustful superhero.

Clearly, however, he maintains his faith in the people around him, understanding of the fact that people aren't born evil, as evidence by his willingness to listen to Zemo in Captain America: Civil War, after which he even seemed to show sympathy, despite the death and destruction the villain had already caused. Cap is clearly a man of principle and humanity, qualities that have become more prominent as the Rogers develops. It'll be exciting to see how his story ends.

14 WORST: IRON MAN

You'd think after three solo films and significant appearances throughout other MCU films, we'd be able to see him grow. The truth is, after his change of heart in the first Iron Man concerning the development and sale of powerful weapons, Stark has remained the same, flawed human being he always was and evidently will always be. Yes, he's charming in his own way and he brings life to every scene he appears in but after a certain point, you start wanting to see more.

He knows he's flawed, he's got a huge ego, he's stubborn and he's addicted to his work. For those reasons, his relationship with Pepper Potts has suffered, or at least, that was what we were told until she turned up in Spider-Man: Homecoming, seemingly accepting of Tony, despite the fact that he hasn't really changed at all in the past decade. The whole MCU seems to just develop around him.

13 BEST: WINTER SOLDIER

Bucky has undergone quite a few changes throughout his appearances and though he's only had a few scenes throughout the MCU, he has become one of the most well developed characters. When we were introduced to him in Captain America: The First Avenger, he was cool and confident. He was a fighter, a lady's man and a loyal and devoted friend. That changed after his apparent death and reemergence as the elusive Winter Soldier. Rogers' childhood friend was seemingly gone and in his place was the mindless killer HYDRA had created.

Even by the end of Captain America: The Winter Soldier, Barnes was still trapped by his mental programming, something that was undeniably clear in Captain America: Civil War when Zemo managed to briefly reactivate the dormant Winter Soldier. By the end of the film, burdened with guilt, Barnes thought it best to return to cryosleep until Wakandan scientists could figure out a way to remove HYDRA's programming, something they've apparently accomplished. His tragic journey may just be coming to a peaceful end.

12 WORST: SCARLET WITCH

We were first (properly) introduced to Scarlet Witch in Avengers: Age of Ultron. Since then, the only other film she has appeared in has been Captain America: Civil War, which wasted her appearance when it had a perfect opportunity to expand on her character and develop her a bit. She lost her brother in one film and inadvertently caused several deaths in the other and yet neither of those films ever really explored how she grew from those tragedies.

Considering how little screen time she had in Age of Ultron, it can be argued that it simply wasn't possible to adequately explore how Wanda dealt with the loss of her bother, but Civil War had plenty of opportunities to explore her character's growth from those tragedies and it just... didn't. It focused on her choice to fight against her own fear and the fear of others, which is great, but it doesn't give us much of a chance to see her really grow as a character the way others have, though it could have easily been written into her scenes.

11 BEST: SPIDER-MAN

One of the reasons why Spider-Man: Homecoming has been constantly praised is because it captures everything that Spider-Man is about as a comic book character: struggle and growth. He's still just a kid in Civil War and that continues to be his issue as a superhero in Homecoming. Then he encounters the Vulture and it changes him quite clearly. He learns to rely on his own strength as we see in that incredible scene when he lifts himself up and out from under a demolished building.

By the end of that film, he makes it known that he doesn't need Stark's help. He's more than just the suit, which is in stark contrast with the boy who seemed to be on the verge of breaking down when Tony took the suit away. In one film, Peter Parker developed more than some MCU characters have grown in almost a decade.

10 WORST: BLACK WIDOW

A shroud of mystery suits the character of Black Widow, but the MCU tends to leave her relatively unexplored. Each film she appears in raises more questions about her but none of them seem to provide us with any answers. We've learned that she's done some terrible things over the course of the career she was forced into, but how does someone deal with all that? Between Iron Man 2 and a Avengers: Civil War, she's had more than enough screen time to develop.

Initially, she appeared almost cold and unfeeling, as you might expect from a trained killer, but Avengers: Age of Ultron revealed that she hasn't yet come to terms with her guilt. That's interesting, that's what we want to see more of and it was left untouched. That's one of the reasons why fans want a Black Widow film so badly. There's a story there that needs to be told and her appearances as a supporting character just aren't cutting it. Recent appearances seem to be pushing her into subplots that do nothing for her character.

9 BEST: STAR-LORD

It's often difficult to find real, meaningful character development in comedic films. Guardians of the Galaxy managed to give Peter Quill an almost perfectly executed character arc. He starts out as a lost child pushed down the wrong path but in the end, he emerged a more heroic figure... not a completely heroic figure but...close enough.

Guardians of the Galaxy 2 built on the questions raised by its predecessor, telling us more about the circumstances that led Peter into the life of a galactic outlaw. Throughout these two films, we see Quill change ever so slightly, but just enough that we can believe the adventures we've seen have actually impacted him. He acted out of self-interest in the beginning but by the end of Guardians of the Galaxy 2, we know that he would never abandon his new companions. It's quite a change and we can't wait to see how he continues to mature in Avengers: Infinity War.

8 WORST: HULK

While Bruce Banner has only had one solo film, the MCU has had plenty of opportunities to develop his character, but it seems intent on keeping him exactly as he is. Anger is a powerful emotion, especially in the way it has manifested in Banner. A lot of the time he seems to be internalizing his anger, keeping it on a leash, so to speak, which is how he's sometimes able to turn into the Hulk at will (although turning back is a bit of a challenge).

Along with Black Widow, Banner was also thrown into a subplot that did nothing for his character. It didn't provide him with any real change. The thing is, it could have been powerful if it were better executed. There was a moment in Avengers: Age of Ultron when Banner spoke to Romanoff and he seemed to confront his truth. The problem is he didn't grow from it. There was no motivation to keep fighting this other side. Throughout his appearances, he seems consistently content with playing host to a monster.

7 BEST: NEBULA

When she first appeared in Guardians of the Galaxy, it seemed as though she was just Thanos' crazed and evil daughter. She allied herself with Ronan and proceeded to engage in the assault on Xandar. For the most part, it seemed she was just a villain through and through. Then she returned for Guardians of the Galaxy 2, and we saw that there was a lot more to her than just that penchant for betrayal and destruction.

She didn't choose to be the killer she is, it was forced on her by Thanos, who quite literally took her apart and rebuilt her as a monster. Despite being largely comprised of the cold machinery Thanos gave her, she's not absent of compassion. In fact, compassion was exactly what she needed, which is how Nebula and Gamora were able to reconnect, not as Thanos' agents but as sisters. She may not have had a lot of screen time but Nebula has evolved a lot and it's been a pleasure to watch.

6 WORST: FALCON

There should be much more to this character than we've seen. When he first appeared in Captain America: The Winter Soldier, he was a former soldier, guiding other veterans through PTSD. We were also told that he had lost his wingman during his time in para-rescue. It all sounds like the beginnings of a great character arc, especially since there's a lot of emotion there to build on, but as we've seen, it isn't.

That's purely because none of the films ever explore the character any further. All of his appearances, following those initial scenes in The Winter Soldier, seem content with limiting Falcon as the guy with one liners or the Cap's sidekick. He is and has always been that guy. You could argue that hasn't had enough screen time, but by this point, other characters such as War Machine or Vision had already seen significant growth. Hopefully Infinity War will give us a defining moment or two for his undervalued character.

5 BEST: BLACK PANTHER

Civil War killed two birds with one stone when it involved T'Challa in the story of Zemo's revenge. The film established who T'Challa was as a man and as a superhero. That's about as much as anyone can expect from a superhero film when it comes to character development. Moments that define the character, like the ending did when T'Challa spared Zemo's life, exhausted from allowing himself to be consumed by vengeance.

It's why Black Panther managed to exceed everyone's expectations, because it wasn't just about T'Challa's growth, it was about how that growth affected all of Wakanda and how Wakanda had affected him. He grew further and further away from the man his father thought he would be, more so after he saw the fallacy of keeping antiquated policies alive and he learned how that level of secrecy and vengeance both had terrible consequences. He's learned and changed a lot in such a short time and the filmmakers should be praised for being able to elegantly show us that growth.

4 WORST: HAWKEYE

The MCU seems to struggle with making Hawkeye seem important to the Avengers. In Avengers: Age of Ultron, he pretty much nailed the ridiculousness when he reminded Scarlet Witch that he was just a guy with a bow and arrow. For that reason, the conversation Clint has with his wife, though somewhat endearing, is risible precisely because they seem to think Hawkeye is in any way vital.

Make no mistake, Hawkeye is an awesome character, but in no way, shape or form can he be seen as the glue that holds the Avengers together, as he implied when he said, "they're my mess." If he was meant to be, then the MCU has done a poorer job than previously thought at showing us that. In fact, Barton has remained pretty much the same character throughout the four films in which he's appeared. That's fine, he's good as is, which is why the MCU shouldn't try to suddenly force more depth than is necessary.

3 BEST: THOR

After three solo films and two Avengers films, Thor is still showing us that there's a lot for him to learn and that he hasn't finished developing as a hero. He was reckless and foolhardy when we first saw him, but he's come a long way since that first Thor film. He has grown fond of Earth and through that fondness he has grown more compassionate about the people and beings around him, regardless of where they come from.

Thor: Ragnarok gave us his biggest change yet. All this time he believed that his strength and power rested within his hammer but when Hela destroyed Mjolnir, Thor was forced to discover the strength he held within himself, embracing his role as the god of thunder. We're eager to see the hero that emerges when Thor faces Thanos and his forces in Infinity War.

2 WORST: DRAX

Drax was given a pretty compelling motive for being so reckless and violent. He lost his family to Ronan the Accuser and sought revenge. Throughout his appearances, he has demonstrated an ability to be compassionate and honorable. Unfortunately for the character, we're only given a brief glimpses of that side of him. The rest of the time, Drax plays the butt of jokes concerning a lack of social ability and an inability to comprehend most metaphors (though he's clearly working it).

It's funny most of the time, but it gets tiresome when those comedic moments come at the expense of time or scenes that seem to offer an opportunity of real character development. The closest we've gotten is the scene he has with Mantis in Guardians of the Galaxy 2, when she conveys the emotions that Drax simply cannot express. They never build on that and as such, even though he's been quite a prominent character in two films, he's more or less the same. He hasn't grown outside of accepting a new group of friends. Every other character around him seems to change but he's stuck in the same place.

1 BEST: LOKI

We've always known that beneath the mischievous, manipulative facade, Loki is just someone lost and looking for the respect he was denied as he grew up alongside Odin's heir. Thor and Avengers showed us just how reckless he could be in his pursuit of that respect and recognition. Things only started to change with Thor: The Dark World and Thor: Ragnarok, in which we saw Loki slowly evolve from the conniving god of mischief to an Asgardian with a decent soul.

He grew closer to his brother and began to appreciate that the things he's spent years pursuing may not be worth it. We know some part of him has changed significantly because, by the end of Thor: Ragnarok, he showed us that there was hope he could become a trustworthy hero, as evidenced when Thor discovered that Loki, not his illusion, was staying by his side on the ship. Only time will tell if Loki has truly abandoned his treacherous ways.