Diablo Noir's figure presents a commanding presence with a flowing, dark cape and sharply detailed armor. The noir color scheme blends deep blacks with subtle gunmetal highlights that catch the light from multiple angles. Intricate sculpting emphasizes the demon lord's horned helm, angular gauntlets, and ornate belt, while a smooth matte finish contrasts with glossy accents on the eyes and weapon to create depth. The pose is poised and confident, with one arm extended as if to invite an unseen duel and the other hand resting on a secondary accessory. Subtle shading across the cloak and armor adds texture, giving the impression of movement and a living, watchful gaze.

Diablo is the supreme demon lord whose power and intellect make him an almost unstoppable force within the world of demons and magic. In the series, he appears as a master strategist, always several steps ahead of his rivals, preferring calculated diplomacy or brutal displays of strength depending on the moment. Although he sometimes serves Rimuru in the long arc, his pride and ancient lineage keep him aloof, treating others as pawns or potential threats. The Noir edition captures this duality, illustrating a character who radiates cold precision, refined taste, and ruthless ambition, while anchoring his presence with a dramatic backstory of loyalty, rivalry, and the pursuit of ultimate rule.