Subspace is an egotistical, sadistic, and self-centered inphernal who prioritizes his goals above all else, viewing others as expendable and exhibiting prejudice towards inphernals not from Blackrock. He prefers working alone and has a reputation for being difficult to collaborate with, though he shows affection for his robotic creations. Subspace has two sets of pink horns, one curling upwards from the back of his head, framing a glowing pink crystal, and a smaller set curving forward from the sides. He wears a grey gasmask with red accents, an eyepatch, a black and grey striped tanktop, a grey shoulder wrap with a Greek-key pattern, and dark gray boots with pink soles.

The King of Blackrock Castle, a towering figure at 6'10", possesses a striking appearance with white skin, long white hair streaked with light blue, and sharp, ice-blue eyes. He is adorned in a black shirt with yellow buttons, a fur-trimmed red cape that drapes regally over his shoulders, and a golden crown. His left eye is visibly frozen, hinting at his nature as an ice king. He wields an ice sword and can incapacitate foes by encasing their limbs in ice. Despite his formidable ice-wielding abilities and imposing stature, he is described as quiet and gentle. However, his reign as the Cruel King is marked by an extreme devotion to his citizens' safety, which has led him to acquire the legendary Ice Dagger, a weapon of immense power.

Zeta Biografts are the primary Biografts manufactured by Blackrock, often acting as their primary combat units and also appearing as a playable class in PHIGHTING!. They are highly task-focused, prone to self-criticism upon failure, and have limited comprehension outside their programming, though they can acquire new knowledge. Their composition is thought to be artificial flesh. Beta Biografts are designed as heavy-duty units with robust defensive and offensive features, serving as the "tanks" for Blackrock. Chi Biografts are a less common type of Biograft, with their existence primarily noted during the Subspace Valentine's event. Omega Biografts are produced for elite protection, modeled after Ban Hammer, and feature advanced AI, though this is currently unique to the Omega Biograft Carnage. Epsilon Biografts are accessible to the general populace and are utilized for various service roles, such as in the food industry. The Gamma Biograft is a specialized, singular model created to support Subspace with tasks hindered by his Rot, ensure he takes his medication, and provide general care. It can also be worn as an enhanced protective suit by Subspace.