|Eren...you don't know it yet, but you'll probably find out soon...why Erwin Smith leads the hope of humankind, the Survey Corps.|
|— Eld urges Eren Yeager to trust in his superiors|
Eld had long blond hair which had a middle parting and a bun folded at the back to keep his hair tied. He also had a small beard. Like most other Survey Corps members, he wore a green cloak with The Wings of Freedom emblem on the back. He wore the same uniform as the other scouts.
Eld was a responsible and firm leader with a strong sense of duty. He did not talk much, but when he did, he spoke bluntly and in a straightforward manner. He also seemed to have been a veteran of sorts as he teased Petra Ral and Oluo Bozado about having wet their pants on their first expedition, and sarcastically referred to them as "fine fearless soldiers." He also seemed to hold some sort of belief of what makes a true soldier, as he lectured Oluo that a kill record alone does not make a great soldier.
When Eren accidentally transformed, he seemed to have been more concerned about the reasoning as to why and demanded an answer from Eren. His reaction was interesting in comparison to his comrades; Oluo threatened to kill Eren, Petra feared for Levi's life, and Gunther demanded evidence from Eren about his transformation and intentions.
Along with the other members of the Special Operations Squad, he had some remorse over his reaction to Eren's transformation as he bit his hand just like Eren, which symbolized a bond between them.
On the 57th Expedition, Eld and the rest of his squad travel with Eren and vow to protect him. Although they are nearly all killed by the Female Titan inside the Titan Forest, the Survey Corps manages to successfully capture it in a trap, which was a plan made by Erwin Smith in order to capture the spy, made possible because Eren decided not to transform and trust in his comrades. Afterward, the Special Operations Squad is ordered to standby while efforts are made to capture the human within the Female Titan. Meanwhile, the Special Operations Squad members have a conversation in which they consider that there could be some kind of spy that actually wants to destroy humanity. However, the operation ends in failure when the Female Titan uses a scream to summon other Titans to her position and is devoured by them, allowing her human host to escape out of the body as one of the soldiers.
Afterward, the squad begins to retreat back to their horses, when a flare leads them off-course. They are ambushed by a person whom they thought to be Levi, but later revealed to be Annie Leonhart, who murders Gunther with the vertical maneuvering equipment before transforming back into her Titan form in order to chase them. Eren is ordered to flee while the surviving squad members engage the Titan in battle. Petra and the others initially seem to have the upper hand. Eld launches an attack and a smoke screen blinding the Titan that allows Petra and Oluo to take out her eyes, then Eld launches several attacks on her arms before Oluo and Petra joined in, severing them and proving them useless.
As Eld and Petra move in for the kill, the Titan suddenly regenerates a single eye and bites Eld in half, also severing his arm. Eld's upper half is thrown to the ground as the Female Titan engages Petra and Oluo, killing them both while Eren looks on in horror.
Later during the Battle of Shiganshina, as Erwin Smith begins to lament the dwindling hopes of his dream, Eld stands among the many fallen Survey Corps soldiers in Erwin's mind, wanting to know if their deaths had meaning.
Eld was a very adept warrior who had a very high kill record of 46 Titan kills (of which 32 were with a team and 14 were solo). He also seemed to have been very proficient with the vertical equipment, using fake-outs with the steel wires to propel himself backwards during an attack in combination with using the vertical equipment to help him brake while simultaneously using the gas exhaustion as a smokescreen to blind a Titan and support his comrades' attack. He was very skillful when using his blades to bring down the Female Titan's arms, as shown by him using a variety of different attacks.
Eld Jinn's Statistics :