The following may contain spoilers for Hajime Isayama’s Attack on Titan, available in English via Kodansha US.
Ymir Fritz and Eren Yeager often align in both their experiences and their beliefs throughout attack on titan. As a child, King Fritz abused Ymir and later, after becoming the first Titan shapeshifter, she became his wife. Throughout this time, Ymir desperately tried to win the affections of her husband, but this only happened when he used her by force and abilities that she saw as a curse. Even after her death, King Fritz’s selfish ways led to Ymir being trapped in the ways while creating the vicious cycle of Ymir’s Subjects.
Eren also fell victim to the King’s selfish ways, but chose to become the one to end the cycle. In his childhood, the boy was exposed to grievous losses, harrowing missions, and heartbreaking betrayals, making for a traumatic youth paralleling Ymir’s. Eren often succumbed to his emotions and was known to fans as a whiny teenager who didn’t know how to deal with his problems. However, after season 4, Eren’s trauma left him stone-faced and emotionless, but a scene with Ymir reminded the audience of who the boy once was.
Eren and Ymir struggle to show their emotions
Eren, despite how he is now, is fundamentally a child unable to cry or process his emotions. She feels she has no right to feel the way she does, and she puts her emotions aside in an attempt to be strong and fight against the world that never served her. Growing up with this façade of a stable person forcing himself to defend himself, Eren lost a part of himself that Ymir seems to represent. Eren feels so much resentment towards a world he constantly took from him, and Ymir feels the same way. So, both of them are angry, crying because they feel very intensely how they were mistreated.
In her life, Ymir rarely showed any emotion. As a slave, she worked silently in the background, and as the king’s wife, she Ymir submitted to her, giving him all of her in the hope that he would love her or free her. If ever she was entrusted with something that Ymir didn’t complain about, she obeyed peacefully like a trained animal because that was all she had ever known until Eren treated her like a person, calling her human because that’s what they both desperately needed to hear. and giving him the choice to choose his own path for the first time. After this, she breaks down and becomes the crying girl Eren once was as the boy comforted her.
Eren and Ymir were mistreated by the world
Eren offers Ymir an alternative to the world she knows, claiming that she doesn’t have to serve anyone and that she can be the one to decide her destiny. These are words that Eren himself would have liked to hear after spending his childhood burdened by the decision to end the world that mistreated him. Eren and Ymir were children who were exposed to an obscene amount of trauma, and neither had anyone to help them process this. He slowly ate them both away until they could no longer see the beauty in the world, and couldn’t justify saving the very universe that broke them.
So when Ymir finally raised her head and stopped hiding her eyes, it’s important to take into account the fact that she’s crying. This is the first real emotion the audience has seen Ymir express and an incredible moment where Eren emphasizes with a little girl that he is like him at her core and gives him back a fraction of her humanity. They have emotions and are allowed to feel angry at the world that mistreated them. Eren is neither a savior nor a liberator, he is deeply traumatized and lashes out because all he can feel is anger. Ymir reminds fans of a time before this; Eren was open and emotional before he believed that being strong also means not feeling anything.
Both Eren and Ymir want the ability to see the end of the fight, trying very hard in their own ways to find the freedom they crave. Ultimately, Eren is unable to save the girl on the roads because his own anger has blinded him. He is chained to his hatred and rage because he is not willing to let them go and admit that he is like Ymir, that deep down he is also a crybaby.