Bill Shelburn⁷

Face and facial features: She has a youthful, freckled and expressive facial structure, characterized by defined features, large and intense light/blue eyes and a penetrating gaze.
Hair: She has blonde/light brown hair, in a classic medium cut with some volume on top.
Build and height: Maintains a slim and stylized build typical of early adolescence, of average height for his age range.
Characterization and clothing: His physical appearance in the role projects a mixture between vulnerability and youthful innocence in the face of disturbing tension moments, wearing casual period/retro clothing typical of the late 90s (t-shirts, sweatshirts and simple capes).

Bill Shelburn's personality during his teenage years (and late childhood) is characterized by very distinct traits that drastically differentiate him from his twin brother:
Intimidating and selfish: Shows a clear inclination towards bullying, dominance, and manipulation in his interactions. He often imposes his will on his brother and other young people in his environment. Cruelty and lack of empathy: Exhibits sociopathic and callous tendencies; reacts to extreme situations in a cold, vengeful, or calculating manner instead of showing compassion or guilt.
Resentful and spiteful: After experiencing traumatic family losses during that period, he channels his pain through resentment and blame towards others (especially his brother Hal), obsessively harboring that resentment. Arrogant and manipulative: He possesses a haughty and narcissistic character that leads him to believe he is superior to others, using cunning to get his way and blame others for his own failures.
Deep down in their heart...they may sometimes feel guilt