Biscoe

Biscoe is the series' main character. After leading a rebellion in Millennion, he manages to end Harry's tyrannical reign and becomes Millennion's boss. Because Brandon protects Harry from his men, Biscoe wants to have Brandon killed as well. However, he changes his mind after Mika begs him and bites his guardsman just so that she can reach Brandon and stop the assault on him.

Personality
Biscoe is a strict person and a stickler to Big Daddy's Code of Iron. As he has said to his guardsmen, if Brandon misbehaves, he won't hesitate to scold or even slap him. And it's proven to be true; he slaps and snaps at Brandon when he almost hurts a Millennion guardsman in a fit of rage.

Despite his seemingly cold exterior, he is actually a caring man. It surfaces when Mika desperately begs him to save Brandon, because he knows that Mika is an orphan. If he doesn't save Brandon, he'll effectively ruin Mika's life, which causes his change of heart.

However, these traits don't go along well together. Being a mob boss, Biscoe has to be strict, but he often can't help but let his soft side surface. Like when he and Norton want to force Brandon to work without giving him the time to recover from his wounds and undergo recovery process, he says in his heart that it isn't what he wants to do. He also finds it difficult to punish Brandon harshly and disagrees with Norton's idea of 'flogging' Brandon with Anti-Necrolyze rifles, although he is supposed to do those as a mob boss.

Brandon Heat
Biscoe initially only wants to have Brandon killed for protecting Harry by hurting his agents, but because of Mika's intervention, he decides to save him. At first, his reason of saving Brandon is only for Mika's sake, but Biscoe gradually sympathizes with him because Brandon shows no ill-will towards him despite how unpleasant he has been. Biscoe is very strict towards Brandon, but he actually cares for him. In Worth, when he discovers that Brandon has requested Dr. William to kill him so that he won't burden Millennion, Biscoe is shocked. He speaks some kind words to Brandon, hoping that Brandon will never have suicidal thoughts anymore. When Brandon resumes his walk with Dr. William, Biscoe admits to his guardsman that he views Brandon, despite his flaws, as an amazing man in Millennion.

Biscoe tends to call Brandon "silly boy" for his awkwardness. Trying not to relive the painful memory of forcing Brandon to put on a prosthetic leg before his surgical wound heals, Biscoe always figures out a way to keep Brandon from fighting when he is injured, no matter how much Brandon wants to. He tends to use Mika against Brandon to keep him locked in place, much to Brandon's chagrin.

Mika Asagi
Biscoe respects Mika because she is Big Daddy's child. However, Biscoe proves to be a kind person to her as well, as shown by him giving his daughter's comics to her.

Norton
While Biscoe respects Norton as his second-in-command and often listens to his advice, they sometimes clash. Unlike Norton, who is more driven by the law, Biscoe can still put the law aside for the sake of showing compassion and empathy.

William Rutherford
Biscoe initially does not have a good relationship with William (although he does respect the doctor to some degree), as William views his way of treating Brandon as harsh and inappropriate while Biscoe is implied to have threatened William if the doctor does not listen to his orders. However, they appear to get along better after Biscoe apologizes to Brandon for what he has done.

Trivia

 * Biscoe appears rather early in the anime. Biscoe_Norton_Alzac_Ep_6_JPG.jpg is first seen along with Alzac and Norton in episode 6 (directly across Big Daddy), in which they are the business associates Big Daddy is talking to.