22 movies in, 11 years later, dozens of characters introduced. Yet one hero is and always been the center of the entire Marvel Cinematic Universe. Our beloved genius, billionaire, playboy, philanthropist. Tony Stark underwent a massive journey since his first appearance in Iron Man. He is presently recognized as arguably Earth’s best defender, willing to put his life on the line to save the world. But many forget the hugely naïve and egotistical idiot he once was.

With that said, the change from zero to hero was a gradual one. It’s the MCU’s longest, and most well-documented journey. And obviously, some moments were more crucial to the character than others. So, without further ado, here are the 10 Most Important Scenes For Iron Man’s MCU Journey.

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10. Sacrifice play

It seems as if Tony Stark undergoes some massive change in every movie he's in. However, none was more apparent than his post-Avengers behavior. After Captain America's confrontation with Tony, (“You’re not the guy to make the sacrifice play”), Earth’s Mightiest Heroes end up having to defend the city of New York from a massive alien invasion.

It ends when Iron Man proves the Star-Spangled Man wrong and (nearly) sacrifices his life by entering the wormhole and the sky to destroy the army’s base. He barely makes it out alive. In Infinity War, Stark tells Doctor Strange that “Thanos has been in my head for six years!”. Turns out six years before that, he was falling from a wormhole in the sky. This was the moment his Thanos-centered obsession began.

9. Father and son...ish

Tony Stark has had many close relationships with other characters, like Steve, Rhodes, and Pepper. But none was more surprising and more pleasing than his fatherly bond with Peter Parker. In an unexpected turn of events, Tony travels to Queens to recruit a 15-year-old superpowered kid to help him fight and capture Captain America and his allies.

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He succeeds in getting Peter to confess the fact he's Spider-Man, in getting him to travel with him to Germany, and in starting an intimate father/son-like relationship. It might not seem like such an important moment, but this is a huge turning point in Tony's life. After going from an immature jerk to a responsible adult, he then enters a new phase of life, which he explicitly references to Pepper in Infinity War. Parenthood.

8. A vision to remember

How Iron Man Became Obsessed With Thanos: Part 2. The beginning of Age of Ultron was the source of probably Tony’s most traumatic memory to date. As the Avengers are outside kicking Hydra butt, Stark makes his way towards the location of Loki’s scepter. Unfortunately, he fails to notice Wanda Maximoff following closely behind him. While he’s distracted, she sneaks up and uses her trademark, vision-inducing powers.

Iron Man jumps back in fright as his mind tricks him into seeing a Chitauri army over a pile of dead Avengers. A dying Steve Rogers then grabs his arm and whispers: “You could have saved us. Why didn’t you do more?” From then on, Stark’s number-one priority became preventing that vision from coming true. His greatest fear became watching his friends die, while he remained alive. Now go watch Infinity War...

7. I am Iron Man

Tony Stark shows off during missile demonstration in Iron Man

Was there ever any doubt this would make it on the list? The movie-ending line is not only a crucial moment in the MCU but also an essential scene that further established Tony Stark's character arc. His split-second decision to drop the whole “Iron Man is my bodyguard” act and simply reveal his identity to the world wasn’t just another demonstration of Stark’s egotistical beginnings.

It was the moment he accepted his new role in life, as protector of the people. He’s no longer an ignorant warmonger, but he’s also over the guilt he felt after his epiphany in Afghanistan. He is now ready to take on the world as something besides weapon-selling CEO. And that something is Iron Man.

6. Iron Man vs Captain America

Captain America: Civil War is one of the MCU's most significant movies, seeing as it is responsible for breaking the Avengers apart. The Sokovia Accords, introduced in the beginning, are enough to steer the team into a series of repetitive internal arguments. However, the end of the Avengers as we know it only comes about in a crucial Tony-centric scene. As he discovers the horrible truth behind his parents' deaths, all logic flies out the window as Iron Man unleashes a never-before-seen rageful monster he has inside.

RELATED: The 10 Most Important Scenes In Captain America's MCU Journey

A vengeful murder machine, ready to kill Bucky Barnes in a heartbeat. The Iron Man vs Captain America/Winter Soldier battle sees both Avengers lose each other's trust and most importantly, their friendship. It's a scene that truly exposes Tony's dark side and one that furthers the plot on the relationship with his parents, with Steve Rogers, and with the Avengers.

5. The Avenger Initiative

Before post-credits scenes were synonymous with Marvel movies, Marvel Studios tried to implement it in their very first outing. In Iron Man's mid-credits scene, Tony returns home to find a shadowy figure waiting for him. He presents himself as "Nick Fury, Director of S.H.I.E.L.D" and proceeds to talk to the host about something called the "Avenger initiative". This is the moment that audiences realized the MCU was no regular franchise.

For Tony Stark, this was the moment he met Nick Fury, realized he wasn't the only superhero in the world and was introduced to the concept of the Avengers. If not for this, Stark would have continued to roam around freely by himself without a Cap, Hulk, or Thor to interact with. And seeing as, until recently, Iron Man was the face of the Avengers, it's hard to imagine the team without him.

4. Final Showdown

For years Tony Stark had predicted the coming of a bigger threat than Loki or Ultron. When Thanos arrived on screen, Tony’s fears were proven to be true. Infinity War finally gave us something we (and Tony) had been waiting for since The Avengers. Iron Man face to face with his greatest fear, Thanos. After the heroes on Titan fail to steal the Gauntlet, the Mad Titan manages to defeat all of them, one by one, until Stark is the only one left.

Thanos surprises the Avenger when reveals he knows Stark. It might just be because both men are very similar. They refuse to give up until their universe-saving mission is complete, making them each other’s biggest obstacle. It ends in an awesome, yet short-lived battle in which Tony manages to make Thanos bleed. Unfortunately, that's not enough to defeat the villain and Tony Stark is nearly killed.

3. Pepper Potts

We can talk all we want about Avengers, alien threats and iron suits, but these are all mere distractions in comparison to Virginia Pepper Potts.  Robert Downey Jr's character has gone through some colossal changes over the years, but his love for Pepper has been present since day one. "I don't have anyone, but you" is what Stark tells his assistant in Iron Man after she replaces his arc reactor.

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In the Endgame trailer, while adrift in space with no hope of surviving, he ends his recorded message to Pepper with "It's always you". It's hard to pinpoint one specific scene, but I'll have to go with one from an otherwise forgettable movie. After Tony rescues Pepper from an exploding Hammer drone in Iron Man 2, he takes her to a rooftop where they end up sharing their first kiss. This marks the official beginning to the MCU's best relationship.

2. Survivor's guilt

Marvel Studio's foreshadowing is unlike anything we've ever seen. Tony's nightmarish vision in Age of Ultron, and his angry rant towards Peter Parker ("If you died, I feel like that's on me") were more than just throwaway moments. They were building up to a truly heartbreaking scene.  There's really no need to explain it but...here we go. Following Thanos' devastating snap, half the universe starts to disappear.

On Titan, Iron Man's allies all turn to dust until only he and Nebula remain. His number one fear in the flesh. As if that wasn't enough torture for a day, he still had to endure having his “son” die in his arms, while he desperately held on to Tony and gasped the now iconic line: "I don't want to go". His second greatest fear. Thank God Pepper didn't die or I think the poor man would just give up on life.

1. A hero is born

The beginning of Tony Stark's decade-long, 10-movie journey. The biggest and most important change to his character was, without a doubt, his escape from Afghanistan. Had he not built that first clunky metal suit "in a cave, with a box of scraps", he probably would have been quickly killed by the terrorists, even if he had built them the Jericho missile.

However, the trauma of being taken by them was only a part of the process that truly made him the man he is today. Witnessing his friend Yinsen sacrifice his life for him is what really brought home Tony's life-changing epiphany. That he was wasting his life on nothing. That he needed to start giving back. That he needed to become a hero. He left that cave with a purpose and a metal suit. A recipe for Iron Man.

NEXT: 8 Ways Marvel Films Have Changed Since Iron Man (For Good)