As much as I have love/hate relationship with this fandom, what I quite can’t understand is how much people try to paint Eren’s actions as one-dimensional or use “because I was born into this world” rather than actually looking into how his actions were explained across the last arc from the moment he finally arrived to Paradis.
As I said here, Eren himself was the biggest mystery of WfP. But as much as he was, Isayama strategically used flashbacks to explain why and what led Eren to what he did.
Overall, the reason for rumbling is divided into: for Eldians and Paradis, for friends, and for freedom.
For Paradis and Eldians
The first flashbacks we got was in ch 106, where they had a meeting to discuss how to work with volunteers and try to understand Zeke’s intentions. Even during that time Armin mentioned how rumbling can protect Eldians and Paradis.
Armin and others were still hopeful about being able to negotiate with Marley and come to a peaceful agreement, but the biggest problem they had is time. There’s physically no time for them to come up with a solution because Marley is still persistent on acquiring Founder’s power and Eldians inside of walls (I talked about it here).
The next set of flashbacks was in ch 107, when Paradis finally met with Hizuru. During the meeting Kiyomi proposed a plan where Eren should activate a small-scale rumbling to win 50 years to advance and get on the same level as the outer world. But the nuance of the plan was that royal family will need to pass the power down from generation to generation, which didn’t align with their morals.
Another catch is that besides the Beast Titan, Founder would definitely need to be passed down as well and the biggest nuance is here…Royal blood Founders would be affected by the vow and there’s no guarantee that those 50 years wouldn’t be wasted. Therefore, Eren said:
Eren knew that they can’t waste any time waiting and entrusting the future to people who weren’t born yet. There’s no guarantee that such a long-term plan will succeed and the outer world will magically come to agreement with the nation that terrorized them for centuries before. The flame of hatred is still hot and fierce. The world want them to be gone as soon as possible. There’s no time left for brainstorming and negotiations.
For friends
Eren’s suspicious behavior sparked a big discussion between Connie, Jean, Armin and Mikasa. They were confused, angry, and lost in why and what Eren is doing. They didn’t know who the person arrived is. It wasn’t Eren they knew, but yet Mikasa was the one believing that he still cares about them, which introduced us to the railroad flashback.
Eren knew that as much as they are excited and hopeful about showing the world that they aren’t monsters and are open to confrontations, they don’t have time because world want them to be gone. They still hate them no matter what they do.
It is undoubtedly that Eren loved them and wanted his friends to be living long and happy lives. He didn’t want them to be burdened with the weight of his fate and choices because he cares about them.
But even then, considering everything that happened in Liberio, they were questioning Eren’s real intentions. They could no longer trust them at that time.
Additionally, we got ch 112 and in ch 116/118 when Jean and Armin said:
They were the people who wanted to know Eren’s intentions behind his alliance with Zeke the most. Then Eren activated the full-scale rumbling in ch 119/122 and in ch 123 we got another flashback.
From Mikasa’s pov, she and others finally understood that the outer world doesn’t want them alive, just as Eren knew. They no longer had time. They “no longer” had Eren on their side.
But even then, Eren was still on their side because he triggered the attack on Liberio that won their side some time. Though, the time they had was not enough and Marley attacked again, and he had to activate the rumbling.
There, they finally understood Mikasa’s words:
Eren partly did it for them too, but did it make them accept the fate and opportunity Eren gave them? No. They fought while being driven by their conscience and morals. They were free to do what they want despite them being confused about Eren’s intention behind it again.
As we l found out later, Eren wanted them to be perceived as heroes and give them a chance to witness the world without walls even if it cost him to bury his humanity and let his desires and passions to consume him. Because he cares about them. He knew that they have their own goals and dreams about peaceful life.
For freedom
The last and the most complicated reason why Eren did this.
Freedom for Eren was not just a concept, it was not just a desire, it was what shaped his mindset and drove him for years.
As I wrote in Eren’s weaknesses, he’s a maximalist with polarized thinking. There’s either everything or nothing for him. It’s all black or white. No in between.
Freedom he desired made him drunk, chained, and enslaved because it didn’t liberate him, but made Eren be focused on achieving something that doesn’t exist nor what he can’t experience. Eren failed to understand that he can’t find what doesn’t exist within him.
The flashback that revealed a big chunk of his personal goal regarding freedom was ch 131, when Eren was crushed by the reality he witnessed. The world beyond the sea and walls wasn’t what he expected. It wasn’t the idealized world he created in his mind the moment Armin showed him the book. He was disappointed, he wanted to vanish it as a child whose parents didn’t give him what he desired.
Eren tried to rationalize other people’s opinion on Eldians being eradicated, but he still couldn’t accept it. It is not how things should be. Reality was too hard for him to comprehend because of how maximalist and immature Eren can be.
Eren knew what he is going to do is extremely wrong, but same as Reiner who wanted to achieve glory by becoming a warrior and attacking wall Maria, he still went for it because that’s what his selfishness wanted.
As much as rumbling brought some benefits to his nation and friends, Eren still had a very selfish and immature feelings about the outer world. It wasn’t just a physical threat to their well-being, but a threat to his idea of freedom, and as any threat…The outer world was supposed to be gone. Even he says that it is in his nature to take away someone’s freedom if they threaten his:
Eren believes that everyone is free from the moment they are born, but yet ironically, he isn’t free in the sense that he defines freedom and free person. But even then, Eren knew he both has and doesn’t have a choice because what he is going to do both brings benefit and violence. It’s both a salvation and destruction that will be caused by his actions.
Eren knew that even if he didn’t know what exactly would stop him in the end (since it’s the result of Mikasa’s choice), he would still move forward with his desires and wishes because that’s what he wanted as irrational and selfish as it sounded.
Conclusion
What I wanted to say, the reason behind Eren’s actions are complex and nuanced. But even then, Isayama showed us that every flashback and situation they had during led Eren to what he did in the end, be it for Eldians, his dear friends or himself.
