Bertolt Hoover

Bertolt was a quiet young man who identified himself as someone with a weak will that follows popular opinion. Likewise, his instructor noted him to be a person with great potential, but an utter lack of initiative. He was further described by Eren Yeager as being taciturn, and Bertolt tended to remain in the background unless necessary. By his own admission, he was somewhat of a coward and was noted for his low self-esteem. His withdrawn behavior initially led to the impression of him being the least emotionally compromised of the three Titan warriors. He showed little attachment or remorse over his actions, seeming to care only about his partner, Reiner Braun. However, when confronted by his former comrades and questioned about their friendship, he revealed himself to be far more conflicted and guilt-ridden than it originally appeared. He showed great devotion to both of his fellow warriors, Reiner Braun and Annie Leonhart, and was easily driven to action or anger when he felt either was threatened. Initially, he showed himself to be wary of others and acted as a voice of reason to Reiner, repeatedly cautioning him about lowering his guard down. His interactions with Ymir also reveal that while his actions have caused considerable suffering, he was not a cruel person and was capable of showing genuine kindness towards others. Bertolt underwent a serious change in character shortly before and during the Battle of Shiganshina. He became detached, indifferent and cold, allowing him to fulfill his savage duty more efficiently. Bertolt remained calm and composed, and did not feel sorry or bad when he told his former friends that he will kill them and all humans inside the Walls because he had decided to do so. He was unfazed by Armin Arlert's attempt at manipulating him by bringing up Annie, did not feel panic or dread when other Survey Corps soldiers were going to kill the helpless Reiner and he had to leave him to himself. He noted how Armin is unable to do anything to him as long as he shakes in fear of his presence. Bertolt did not show complete disregard for the human race and his 104th Training Corps friends. He showed panic and slight tears when he, Reiner, and Annie left Marco Bott to die. When confronted by Armin, he referred to his former comrades as "cherished friends" and repeatedly stated that they are not at fault. This leaves the impression that Bertolt's reasons for wanting them to die were not personal, and were due to unknown factors outside of their current comprehension or knowledge. Bertolt once more showed sympathy for his old friends by expressing his disappointment in the waste of Armin's intelligence as he dies. He then decided to burn him as quickly as possible to put him out of his misery. Bertolt came to accept his villainous self, and rationalized that none of it was his or anyone's fault, but that the world is cruel, and all of it was inevitable. When the blast of his transformation failed to kill all of the soldiers, he expressed his disappointment at his former friends' continued survival. Despite his calmness and utter fearlessness in the face of death and destruction, Bertolt was absolutely terrified of the thought of dying himself. As Armin's Pure Titan approached him, Bertolt frantically begged his former friends to save him then cried and screamed for Reiner and Annie before being brutally devoured.

Human form
Bertolt was a rather tall, slender young man. He was the tallest of all currently known holders of the power of the Titans. He had short, dark hair, brown eyes, thin eyebrows and an elongated face. He was seen mainly in his Trainee uniform, and after he entered the Survey Corps, he used their uniform. After his encounter with the Beast Titan, his hair appeared shorter and wore a trench coat. During the Warriors' battle in Shiganshina against the Survey Corps, Bertolt wore a set of vertical maneuvering equipment along with a collared shirt and dark pants.

Bertolt graduated in 3rd position among the trainees and was noted as the best user of the vertical maneuvering equipment among them. He managed to kill a small Titan without the use of the vertical maneuvering equipment. Due to his high-level position, he is also likely to possess other military and combat skills. Furthermore, he had outstanding marksmanship skills when he was a child training among the Warriors. Bertolt was also able to defend against and even temporarily overpower Mikasa Ackerman in combat, despite her attacking from behind.