When The 100 began, the hundred were a group of delinquents struggling to survive on the ground, and the council was desperately trying to conserve oxygen but by the end of the first season, there were severe differences in where the main characters landed. Afterward, everyone had to learn what it meant to make life or death decisions.
Everyone showed character development during the seven seasons as their lives made it impossible not to. However, some experienced more than others due to their amount of time on the show or how involved they were in making massive choices.
Updated on April 28th, 2022, by Kevin Pantoja: The 100 started as a show where the characters were trying their best to survive but it eventually grew into an epic sci-fi series where these people were literally tasked with saving humanity. That's a lot to ask, especially for people who are still very young. However, due to the events of The 100, each of these characters has been through so much that they are actually kind of well prepared for this situation. Some became great leaders, others became tougher people, and a few went from villains to heroes, all completing impressive character arcs along the way.
Echo
It isn't that Echo doesn't show character development. It's that Echo's most massive growth occurs off-screen. Echo receives one flashback in season 7 that shows when she changed her loyalties to Spacekru. However, there are never any other scenes that show Echo's bond with anyone other than Bellamy.
Echo is an integral part of the group from season 5 and onward, but it occasionally comes across as out of place without knowing what happened during those six years. It becomes more confusing when Echo's six years on Skyring, which the viewers get to watch, lacks the emotional weight of the relationships Echo made in space.
Monty
Monty does grow throughout his time on the ground, but he always remains consistent. Monty is, in a lot of ways, a steady rock of the group. Although Monty made it possible to irradiate level five, he doesn't have many impossible decisions weighing him down.
Monty may fight to help his friends, but he has never wanted to go to war. Instead, Monty's final arc shows his wish for peace and to avoid war. Later, he chooses to stay awake with Harper to have a happy life instead of fighting to survive and he still manages to be the guy who saves his friends.
Abby
Abby's arc is more of a spiral toward antagonistic territory. Her choices on the Ark may have raised eyebrows and angered some, but she becomes something far worse after touching the ground. Abby struggles as a leader compared to Clarke's experience with the Grounders, and it only gets worse from there. She really goes off the rails in season 5.
Abby suggests cannibalism, then insists that Octavia make it illegal not to eat while also deciding that Kane had to give in first. She also used Raven's shock collar to electrocute her because of Abby's pill addiction. In season 6, Abby is so consumed with trying to save Kane that she doesn't realize that her daughter has been body-snatched.
Emori
When Murphy met Emori, she was just like him. Cast out and desperate to survive, Emori was looking out for herself and wasn't interested in helping others. But, after teaming up with Murphy, Emori began to care about him, and the two latched on to each other as the apocalypse was set to arrive.
In space, Emori grew to be friends with Raven, learning about technology and engineering. In the series finale, Emori tells Raven that if the choice is between her and the entire human race, to save the human race. This is a drastic difference from the perspective Emori had when she was first introduced.
Raven
In a lot of ways, Raven is the smartest person on the show. Capable of building just about anything, Raven has helped save the day on more than one occasion. One of the most intriguing aspects of her arc is how it grew in the final season. Raven had always been complicit in everyone's worst choices, even if she disagreed.
Yet, Raven spent a lot of time blaming others and ignoring her role in the events. When Raven had to make the difficult choice about the radiation chamber, she finally understood how it felt to make the tough call. She has the ability to understand why an awful action needed to be done and what it takes to live through it.
Kane
From being one of the biggest problems on the Ark to one of the most loved characters, Kane grew plenty during the six seasons. Kane had lived his life to the letter of the law for the sake of humankind. While that didn't make him popular amongst the Ark's citizens, it was also a trait that brought about issues after touching Earth. The Ark's rules couldn't apply on the ground, and as times changed, Kane changed with them.
He wanted peace with the Grounders, and instead of sentencing people to death, he wished to protect and save them. Kane died because he refused to live within another man's body and, in his death, brought the Nightblood with him.
Clarke
Clarke undergoes a lot of character development as she is constantly placed in a position to make life or death choices. Clarke Griffin, nicknamed Wanheda in season 3, had become a force to be reckoned with. Similar to Monty, Clarke's goals have always been consistent.
From the beginning, all Clarke wanted to do was protect her people. That never changes throughout the show and as time goes on, Clarke becomes more passionate to protect those she loves. Even in the series finale, Clarke is prepared to bear it so her friends don't have to.
Bellamy
Even with Bellamy's maligned final storyline, he does undergo one of the biggest character developments. Bellamy went through a lot as he struggled to be the best leader he could be. Bellamy was not the best person initially, but by the end of season 1, the real Bellamy had begun to shine through. In season 5 and afterward, Bellamy's biggest desire was to live in peace, which was a huge difference from his willingness to engage in war during earlier seasons.
He also shows development in his relationship with Octavia. The two had struggled in their relationship for a long time. In season 6, Bellamy finally acknowledges that Octavia is his sister, but not his responsibility. With Octavia's development at that point in her redemption arc, the two could have had a chance to begin repairing some of the damage between them.
Murphy
Murphy goes through some of the most monumental changes. First appearing as an angry delinquent at the Dropship, Murphy slowly transforms into a reliable friend. While he does earn his nickname, "Cockroach," his survival skills begin to come in handy for more than just himself. Part of Murphy's development began after getting close to Emori.
Then, Murphy became a team player to avoid Praimfaya, eventually becoming a vital part of Spacekru. Murphy's changes are most noticeable in the final season when instead of changing sides, as he had with Josephine, Murphy remains strongly beside Emori. Murphy helps protect the people of Sanctum, being extra aware of protecting the children, which is a far cry from the self-preserving survivor he once was.
Octavia
Octavia Blake may have had the longest journey of anyone else. She landed on the ground known for being the illegal second child. Over time, Octavia grew into a warrior, becoming close with Lincoln and Indra. She was the fighter Skaikru needed in the Conclave. After having a furious fourth season, she seems to have made peace, at least at the moment, with how she wanted to move forward. Unfortunately, Octavia's path wouldn't stay consistent for long.
Time in the bunker brought about Blodreina and the Dark Year, two aspects that took Octavia a long time to move beyond. 10 years on Sky Ring allowed Octavia to grow, but even when she returned to Earth, it was difficult for Octavia to step foot in the bunker. However, after years of fighting, Octavia showed her most massive growth by saving the human race, understanding that the best way to survive what comes next is not to fight a war.