TV-Series
Description
Bak Chang is the Branch Head of the Asian Branch of the Black Order, a position he inherited as part of his family's legacy. He is the son of Twi Chang and Edgar Chang Martin, the former Branch Head and Assistant Branch Head of the Asian Branch, who were also the overseers of the Second Exorcist Program. His lineage traces back to his great-grandfather, a German sorcerer who was one of the founders of the Black Order. This heritage grants him unique abilities tied to his bloodline and the mystical seals protecting the Asian Branch headquarters.

Physically, Bak is a slender man of short stature, standing at 168 centimeters, which makes him the same height as the much younger protagonist Allen Walker. He has short, messy blonde hair that falls over his face. His typical attire as Branch Head consists of a customized white bolero jacket bearing the Order's Rose Cross on the left side, Italian-style boots, and a beret with a tassel and a spirit stone on top. He has tattoos on both arms, which are not decorative but rather sorcery contract marks worn by all sorcerers of the Chang Clan as a sign of their oath to a sealed god.

Bak's personality is a complex blend of responsibility and eccentricity. Like his counterpart Komui Lee at the Central Headquarters, Bak is fully aware of his duties and the dark legacies that surround the Black Order. He carries himself with pride in his family name and his own abilities, sometimes referring to himself as "Ore-sama" when angry, a grandiose and self-aggrandizing term, though he normally uses the more modest "boku". Despite his noble upbringing and strict education, he has several unusual quirks. He is prone to breaking out in hives across his entire body when experiencing strong emotional disturbance, a condition his subordinate Wong treats as life-threatening. He also has a tendency to cry without realizing it. Perhaps most notably, Bak harbors a significant crush on Lenalee Lee, maintaining a collection of her photographs in what could be described as stalker-like behavior. He keeps this secret partly because of his friendship with her brother, Komui, who is famously overprotective of her. His sense of direction is notoriously poor, as it is suggested he was once lost in the Asian Branch's own basement for nearly two weeks and almost starved.

Bak's motivations are rooted in a deep sense of duty to the Black Order and his family's legacy. He is a responsible leader who is dedicated to protecting the Asian Branch and its members. His mother raised him with a strict education, believing it would give him the position of a supervisor who could change the negative aspects of the Order. This suggests a desire to reform the institution from within. He is deeply disturbed by the Order's darker projects, such as the Second Exorcist Program, which created artificial exorcists, and he voices his disgust toward the subsequent Third Exorcist Program.

In the story, Bak serves a crucial supporting role. He first appears after Allen Walker is defeated by the Noah, Tyki Mikk, and his Innocence is destroyed. Bak takes the injured and powerless Allen into the Asian Branch, training him and providing the environment for his Innocence to regenerate. When the Level 3 Akuma known as Thread attacks the branch, Bak initially refuses to let a weakened Allen re-enter the battle, only relenting due to Allen's sheer determination. He later participates in the defense of the Central Headquarters when it is invaded, helping to create a talisman to trap Akuma and suffering serious injuries in the process. He is also present during the arc involving Alma Karma and the Third Exorcists, where his personal history becomes directly relevant.

Bak's key relationships are integral to his character. He shares a close and often humorous friendship with Komui Lee, who affectionately teases him by calling him "Bak-chan," playing on the similarity between his last name and the Japanese honorific. His most significant relationship is with Fo, the guardian deity of the Asian Branch, whom he can summon using his spirit stone and blood. Despite her calling him "Baka-Bak," which means Idiot-Bak, they share a deep bond, and he rushes to protect her when she is injured. He is served by his loyal attendant, Wong, who frets over his health, especially when the hives appear. His relationship with his parents is defined by tragedy; both were killed by the Second Exorcist Alma Karma nine years prior to the main events of the story. Because Bak strongly resembles his father, Edgar, the awakened Alma Karma later mistakes him for the man.

Throughout the series, Bak undergoes notable development, particularly in confronting the dark legacy of his family. While he was always aware of the Black Order's questionable practices, events like the rampage of Alma Karma and the revelation of the Third Exorcist Program force him to face the consequences directly. His parents' direct involvement in the creation of the Second Exorcists, and their subsequent deaths at the hands of their own creation, is a heavy burden that he carries. He shows a growing willingness to challenge the Central Headquarters and figures like Malcolm C. Leverrier on ethical grounds, even if his protests are sometimes silenced.

Bak's notable abilities are distinct from the Exorcists who use Innocence. He is a master scientist and sorcerer whose intellect is said to match that of Komui Lee. As a member of the Chang Clan, he can perform sorcery, most often used to control the structure of the Asian Branch headquarters due to the seal created by his ancestor. His primary combat ability is summoning Fo, the guardian deity, by dripping his blood onto his spirit stone and chanting an incantation. The power of the stone is not infinite; it cracks and can shatter if Fo takes damage. He can also use his blood and sorcery to create barriers and restraints against Akuma. Beyond his mystical abilities, he is a skilled scientist and leader, respected for his intellect and dedication to his branch.