In the beginning, Eren Yeager appeared as a typical shonen protagonist, a hot-headed underdog ready to take on the world to save his friends. But Attack on Titan has aged well and across these years we are convinced that Isayama doesn’t like a typical shonen hero concept. There are lots of things going under his sleeves; this new approach to an entirely different protagonist is a culmination of humanity, life, prejudice, and history.
The initial shonen approach to his character was him exploring the world outside the walls while joining the survey corps to save the world from the roaming titans. During the Shiganshina arc, he lost his mother and decides to seek revenge for her, and makes the vow to erase every single titan from the face of the earth. After his graduation, during his first mission, he comes to know that he possesses a hidden monster, the attack titan.
But as we reach season 3’s end it brings a new angle to fans’ perspective towards Eren Yeager, his morality started to fade away and now he owns a moral gray area. The female titan arc shattered his world’s view as he witnessed the dark side of humanity, the clash of the titan arc breaks him a little more he learned about how rotten people within Wall Sheena really were. He starts to move away from the cliché shonen hero.
The transition to season 4 kicked the intricacy and unpredictability of this already complex series sky-high. Now the story has turned from “fighting titan for the sake of human survival” to “revealing titans’ real identity and a sympathetic angle towards them”. Eren Yeager turned intrinsically patriotic with the revival of how Eldians from Marley were advocating for the annihilation of Paradise Island’s people.
This sets him out on the path of destruction; he is willing to acquire power by any means possible. What made Eren Yeager more controversial was when he stopped caring about others and just wanted triumph. He forced his scouts to back him up to raid on Marley without bothering about the consequences and hence, we lost Sash. He doesn’t fear to threaten and use force; he is just pledged to the Eldian nationalist cause.
He might lose his humanity for the cause. It doesn’t matter who comes in his way whether it is Queen Historia, the military, or Mikasa, his only allies are those who want to destroy Maldians.
From shonen hero to anti-hero and finally, to villain Eren Yeager has become a debatable character. His decisions have garnered both praise and disgust. He is a complex character with a very specific and unique morality.