Goyle serves as the Police Chief of his division within the Demon World Acropolis, holding a position of significant authority and responsibility for maintaining peace and order in that region. He is a demon who appears as a young man with spiky black hair, pointed elf-like ears, orange eyes, and a thin devil's tail, often dressed in a tie and his signature thick-framed glasses which are a notable aspect of his appearance.

In terms of personality, Goyle is characterized by a strict sense of duty and a respectful demeanor, particularly toward his superiors and those he perceives as holding rank. He takes his job as a law enforcement officer very seriously, approaching his duties with a conscientious and deliberate manner. However, this composed exterior belies a quick and powerful temper; he is known to be short-tempered, especially in response to criminal acts or disrespect shown to the king. A unique and defining quirk of his character is his profound passion for eyeglasses, which extends to complimenting others on theirs and even owning a coffee mug decorated with a drawing of glasses, while also reacting with extreme displeasure to any taunts or insults directed at them.

Goyle is a loyal servant to the current king of Demon World Acropolis, Wolf Daddy, and sees the enforcement of the realm's laws as his primary motivation. His role in the story is that of an enforcer and an obstacle, most notably when he is tasked with pursuing the powerful vampire Braz D. Blood after Braz escapes from custody and declares war on the king. Goyle uses his authority and abilities in a determined attempt to recapture Braz, showcasing his dedication to his duty.

His key relationships are primarily professional. He is the direct superior of Beros, another officer, and while he may not display overt affection, he holds a degree of fondness for her and becomes enraged when he believes Braz has harmed her. His interactions with Braz are more complex, beginning with politeness and respect due to Braz's status, but quickly escalating into a hostile pursuit driven by duty and anger. Despite this conflict, a grudging and tension-filled rapport is established when they are forced to negotiate, even agreeing to a temporary ceasefire to get ice cream, though the atmosphere remains dense with animosity.

Goyle possesses special magical abilities known as dispensations, or privilege magic, granted to him likely due to his high-ranking position as a law enforcer. These powers are intrinsically linked to his emotional state. His primary ability is called Spear-head of Fury, which manifests from his anger. When he becomes enraged, the emotion physically spills out of his mouth as a purple liquid that forms into a small, dragon-like creature named Angry. This creature is a direct extension of Goyle's wrath; its sole purpose is to seek out the source of his anger, and its power grows in proportion to the intensity of his fury. Angry can also shapeshift, merging with Goyle to form organic gauntlets that enhance his punching power or wings that grant him the ability to fly. His second dispensation is Cool Decision, which activates when he is calm. This ability instantly freezes any opponent who touches his forehead, making them immobile. However, maintaining this frozen state requires Goyle to remain composed; any disruption to his calm, such as a sudden outburst of anger, will break the effect. A third ability, Anger Wave, allows him to send a wave of intense emotion through an opponent, completely relaxing their muscles and causing them to fall into a deep sleep that can last for an entire day. As a character, Goyle shows little personal development, remaining a steadfast and capable agent of order whose primary function is to enforce the king's law, though his encounters with Braz reveal a slight capacity for negotiation and a shared disappointment when his own powers fail to perform as expected.