Bear Walken is a high-ranking executive of the Millennion crime syndicate, serving as one of the organization’s most seasoned and respected members. His role within the family is that of a veteran sweeper, essentially an assassin and enforcer, and he commands his own elite hit squad known as the Overkills. Walken is a figure from an older generation, having been a close confidant of the syndicate’s founder, Big Daddy, and his history is deeply intertwined with the organization's rise to power. Before joining Millennion, Walken was a powerful gangster engaged in a violent rivalry with another criminal, Cid Gallarde. Their feud was only ended by Big Daddy’s direct intervention, after which the two former enemies united under Millennion and became best friends.

In terms of personality, Walken is defined by his calm, collected, and solemn demeanor. He handles all matters with a sense of gravity and carries himself with an authority that commands respect from everyone in the organization. He is a man of principle, albeit one whose principles are often tested by the harsh realities of his world. Walken holds a deep-seated distrust for Harry McDowell, recognizing his ambition and ruthless drive from the beginning. He famously dismissed Harry's attempts at charm and flattery, preferring to judge him by studying his eyes, believing that "the eyes never lie". Despite this distrust, he ultimately approves of Harry as a husband for his daughter, Sherry, having detected the willpower that would allow Harry to rise to the top. This decision, made to protect Sherry’s happiness, binds his loyalty to Harry, even as he inwardly disapproves of the new, more corrupt direction in which Harry takes Millennion.

Walken’s primary motivation is the protection of his daughter, Sherry. As a widowed father, his every action is ultimately filtered through the lens of ensuring her safety and happiness. This paternal instinct is so strong that it leads him to make a pact with a man he does not trust, tying his fate to Harry’s to remain close to Sherry. He is also motivated by a sense of duty and memory toward the old Millennion and Big Daddy. He frequently reflects on the sins he has committed under Harry’s rule and internally apologizes to the late founder, feeling he has betrayed the original ideals of the family. His actions are also driven by a profound sense of honor and friendship, most notably seen in his inability to execute his best friend Cid for betraying the family, a task that falls to a young Brandon Heat.

Walken’s role in the story is multifaceted. Initially, he serves as a mentor to the protagonist, Brandon Heat, teaching him the skills of a sweeper and witnessing his rapid rise as a coldly efficient operative. After Brandon’s death and Harry’s ascension, Walken becomes one of Harry’s Big Four, his most powerful and trusted subordinates, acting as a major antagonist to the resurrected Grave. He represents the old guard who has compromised his principles for the sake of family, serving as a tragic foil to Grave, who has abandoned his humanity for revenge. His internal conflict is central to his character; he is not an evil man but one who has made morally ambiguous choices for what he believes is a noble reason.

His key relationships are central to his character arc. His bond with his daughter, Sherry, is the cornerstone of his motivation. His relationship with Harry McDowell is one of tense, pragmatic alliance, where he serves his son-in-law out of necessity rather than genuine loyalty. His past with Big Daddy fills him with a sense of guilt and nostalgia. His friendship with Cid Gallarde is a tragic mirror to his own situation, as both men ultimately betray the family’s code for personal reasons, though only one is executed for it. His relationship with Brandon Heat is particularly complex: Walken is his former mentor who feels a sense of nostalgia upon seeing him again, but he is also his determined adversary, believing he must kill Brandon to protect the world Sherry lives in.

Over the course of the story, Walken develops from a legendary and principled enforcer of Big Daddy’s old guard into a compromised but resolute protector of Harry’s new regime. He undergoes the process of Superiorization, a procedure that grants him immense superhuman power at a great personal cost, specifically to stand on equal footing with the monstrous Grave. This physical transformation is a manifestation of his moral compromise; he becomes a monster to protect his daughter. His development culminates in a final, honorable duel with Grave, where he fights not as a Millennion soldier, but as a man, seeking to end the threat to his family. Accepting his defeat and death, he finds a measure of peace, having stayed true to his ultimate goal until the very end.

In terms of notable abilities, Walken is an exceptionally skilled marksman and gunslinger, having been the top sweeper in Millennion. He is also proficient in swordsmanship, often preferring a katana in his final confrontation. After undergoing Superiorization, he gains the ability to transform into a powerful, multi-armed form. In the anime, this form grants him five arms, immense strength, and the ability to control disembodied arms to restrain his opponent. In the game, his Superior form is depicted with a single, grotesquely enlarged arm. His power is such that he can slice through Grave's coffin with a single sword stroke and pull helicopters from the sky, making him one of the most formidable adversaries Grave ever faces.