Who is mark

Mark, also a sixteen-year-old boy, is Bryon’s best friend and adoptive brother. He saw his parents shoot each other in a fight when he was a child. He was an illegitimate son. He has distinctive golden eyes and blond hair, like a lion. He has a demeanor of disarming innocence and wildness, since he is persuasive and can get away with anything. He also has no regard for laws or rules. He loves Bryon more than anyone in the world, considering him his only family left. However, he also has no sense of morality, and has no problem selling drugs to children. He becomes even more dangerous after he goes to jail at the end of the book.