At the beginning of Attack on Titan, Eren Yeager is the heroic protagonist. He joined the Survey Corps, hoping he would eradicate the Titans and avenge his losses. Unfortunately, his story didn't follow the typical upward trajectory of other Shonen leads. Eren became an anti-hero and plummeted into the dark side. By the manga's end, he became Attack on Titan's main antagonist.

In fact, Eren's final decision put all of humanity in jeopardy, forcing his friends to fight against him. Although they didn't want to at first, people like Mikasa and Armin had to defeat Eren after he started the Rumbling and wiped out most of the world's population. Though it seems like an unexpected twist, there were numerous warning signs that Eren would eventually descend into darkness.

Updated on March 13, 2024, by Ajay Aravind: Eren has always been the central focus of Attack on Titan, even if his character arc went from naive heroism to apocalyptic villainy. Fans have long wondered what led Eren to take this path, but it wasn't a single moment that affected this drastic change. As such, we've updated this article with some more relevant information.

10 Eren Has Always Been Reckless & Violent

He Turned To Violence At A Shockingly Young Age

Eren's reckless personality and tendency to disregard everyone around him was a red flag from the jump. He constantly kept rushing into battle, a typical Shonen characteristic that went too far in his case. Eren didn't even see the issue with Erwin's plan for him to fight the Female Titan in Stohess District, despite the obvious amounts of collateral damage that would result.

When Eren Yeager and Mikasa were younger, he killed her kidnappers and encouraged her to indulge in the same violence, even if he didn't display this level of brutality for several years after. Though this was to defend someone else, it's still concerning that Eren was so willing to turn to violence at a young age. Retrospectively, it points to him becoming a violent antagonist by the end of Attack on Titan.

9 Eren Said That He Would Destroy The World

This Could Be The Result Of Future Memory Inheritance

Back in Attack on Titan's first season, Eren lost control when he went into his Titan form. He went berserk and said something pretty concerning. After defeating Annie in Stohess, Eren kept punching her. Since she was already unconscious, it was overkill. Everyone was trying to get through to Eren and tell him to back off.

However, Eren was already drunk with power at that point. He had a major adrenaline rush from the sheer amount of violence he was committing and didn't want to stop. At that point, he said, "I'll destroy the entire world!" Some fans might argue that this was the result of Future Memory Inheritance, an ability he picked up from the Attack Titan. In other words, Eren already knew that he was going to usher in the apocalypse, making this a foreshadowing event.

8 Eren Hated The Titans After His Mother Was Killed

Ironically, He Was Directly Responsible For Carla's Death

After the raging Colossal Titan broke into Shiganshina, hundreds of Titans entered the walls. They indiscriminately killed and consumed many innocent civilians, including Eren's mother. Eren and Mikasa tried saving her, but she insisted that they run away and sacrificed herself. Hannes forcibly removed them from the scene, but Eren kept looking back and saw his mother get eaten alive by the Smiling Titan.

Initially, this pushed Eren to join the Survey Corps and become a hero. Unfortunately, it led him down a darker path later on. After discovering that he's a Titan Shifter himself, it changed his perspective on things. After discovering that most mindless Titans were former humans, he realized that everything isn't always what it seems. Interestingly, it was revealed at the end of the manga that Eren was also responsible for Carla's death.

7 Eren's Perspective Changed After Becoming A Titan

The Existence Of Titan Shifters Impacted Him Greatly

Initially, the audience was led to believe that the Titans were the only villains that the heroes would face in Attack on Titan. The island of Paradis had been plagued by these creatures for decades, so the Eldians already believed that they were the last of humanity. However, things grew more complicated with the addition of Titan Shifters. Eren becoming one himself suddenly changed his perspective on the world.

Although Eren inherited the Founding and Attack Titans from Grisha, he didn't know that he ate his own father to obtain those powers. After leaving the Cadet Corps, he discovered the true potential of his Titan powers. He originally used them to help the Survey Corps, but eventually used them for much more sinister reasons following the time skip. It could be argued that Eren may not have resorted to violence had he not become a Titan.

6 Eren Was Hardened By His Friends' Deaths

They Eventually Contributed To The Rumbling

Witnessing his mother's death was traumatic enough, but seeing countless allies die in front of him was a major factor in Eren's fall to the dark side. Several of his friends died when the Titans invaded Trost, including Marco Bott, Thomas Wagner, and Mina Carolina. Then, he joined Levi's squad and felt guilty after his comrades were all killed during their battle against the Female Titan.

The more friends he lost, the darker Eren's mindset became. The audience and main heroes were equally as disturbed when Eren started laughing over Sasha's final words. In some ways, all the deaths he had to experience hardened him to the ways of the world. In other ways, it contributed to the emotional upheaval and psychological turmoil that drove him to start the Rumbling.

5 Eren Felt Betrayed After Learning His Friends Were Titans

Reiner, Bertholdt, and Annie Hurt Him Deeply

Though Eren lost plenty of his friends during battle, he lost three of them for a completely different reason. He felt betrayed when he learned that Reiner, Bertholdt, and Annie were his enemies. Annie the Female Titan was first identified by Armin, and a plan was put into place to capture her. Meanwhile, Reiner and Bertholdt were the Armored and Colossal Titans who broke down Wall Maria and destroyed Shiganshina.

They weren't the closest of friends, but they did train alongside each other. They had a sense of camaraderie that regular everyday acquaintances just don't have. More importantly, Reiner even asked Eren to abandon his actual friends. Therefore, it made sense why Eren was so shocked and hurt by their true identities. As such, it explains why he lost even more faith in the world.

4 Learning What Was Beyond The Walls Shook Eren

His Moral Compass Began Losing Its Focus

Eren always wanted to know what was in the basement of his childhood home. After the second battle for Shiganshina, he went with a few other Corps members to the basement. After using his father's key to unlock it, he was displeased with what he found, since he had always believed that Titans were the biggest threat to humanity. However, it turned out that the people beyond the walls despised Eldians for the actions of King Fritz thousands of years ago.

The whole world wanted the Eldians gone as retribution for their ancestor's crimes. Eren couldn't deal with this fact, as the Eldian people were his family and friends — and those he had sworn to protect. Learning that his country was hated by other people for their former crimes affected Eren's moral compass so much that it began losing focus.

3 Getting A Glimpse Of The Future Terrified Eren

In The End, He Was Unable To Change Destiny

Since Historia has royal blood and Eren inherited the Founding Titan, he saw the future when he kissed her hand. He was terrified after seeing the monster he would become in a few years. He knew he wouldn't be able to stop it. This was one of the biggest contributing factors to Eren's downfall. Eren despised the person he saw in the future and desperately tried to find another resolution.

Unfortunately, the red strings of fate dictated that the only end to Eren's story was for him to become the world's greatest enemy. Knowing the future and being unable to stop it became Eren's greatest regret, which was why he explained himself to all his friends through the Founding Titan. According to him, he simply had no other choice but to trigger a global apocalypse, at least if he wanted the Eldians to be free.

2 Eren Tricked Zeke Into Teaming Up With Him

His Brother Didn't Realize The Truth Before It Was Too Late

When Eren went to Marley on his own, he secretly met with Zeke. However, Eren acted like a caring brother in order to deceive him. Zeke wanted to perform Eldian Euthanasia by effectively preventing the Eldian race from having more children. This was probably the best option, considering the interests of the world, but Eren was more focused on saving Paradis. As a result, he pretended to agree with Zeke's goal and Zeke fell for it.

This allowed Eren to begin the Rumbling when they finally entered the coordinate. If Zeke had been more cautious around Eren, he would have been able to achieve everything that he worked for and Eren wouldn't have killed 80% of the world's population. Unfortunately for Zeke, he gets front-row seats for the apocalypse, only to be finally beheaded by Levi Ackerman.

1 The Yeagerists Led Eren To Plunge Into Villainhood

Floch's Influence Was Probably The Worst Of All

When the Anti-Marleyan volunteers arrived in Paradis, everyone was skeptical about working with them at first. They refused to let Eren anywhere near them. However, Eren and Yelena eventually met, bringing the former closer to Zeke. However, he and Floch secretly teamed up to form the Yeagerists, overthrow the Paradis government, and trigger the final plan.

Even though it wasn't the Anti-Marleyan's intentions, they helped enable Eren's eventual plunge into villainhood. He turned his back on the Survey Corps and was deadset on tearing everything apart. All things considered, however, the blame falls squarely on Eren and the Yeagerists, whose intentional bigotry led straight to the Rumbling. The remaining Yeagerists would go on to influence Paradis politics for years down the line.