Shell Septinos manages the Eggnog Blue casino, funded by the October Corporation. His criminal activities involve murdering women and transforming their bodies into blue diamonds, worn as rings. This pattern originated with his mother, whom he killed due to childhood sexual molestation by her. To evade confronting his guilt, Shell digitally excised these memories, storing them as data.

He maintains a business alliance with Octavia October, daughter of October Corporation owner Cleanwill John October, who is revealed as a pedophile; Shell's awareness or involvement in this aspect remains unspecified.

When former prostitute Rune Balot, once under his control, becomes a witness against him, Shell attempts to murder her by trapping her in a car and detonating it. After she survives through cybernetic reconstruction, he repeatedly hires assassins to eliminate her. These include the mutilative Bandersnatch group, known for using human body parts, and later, former freelance officer Dimsdale Boiled. Shell's primary objective is preventing Balot from testifying in his ongoing murder trial.

His actions demonstrate a consistent pattern of evading accountability through violence and manipulation, rooted in his traumatic past. No significant redemption or moral conflict appears in his arc; instead, he intensifies efforts to suppress evidence and maintain power using the October Corporation's resources.