Jack Howl is a first-year student belonging to the Savanaclaw dormitory at Night Raven College. Despite his junior status, he possesses an incredibly tall, bulky, and muscular build that makes him stand out among his peers. He has dark or tanned skin, silvery-white hair that spikes upwards, and sharp golden-brown eyes. He also has prominent wolf-like ears and a large, fluffy tail that match the color of his hair, fading to a darker gray at the tips, as well as visible sharp fangs. His Savanaclaw uniform consists of a sleeveless dark-yellow shirt, a black leather vest over it, worn gray jeans, black biker boots, and several beaded necklaces, including one with a fang pendant.

Jack initially comes across as cold and distant, preferring to rely on his own strength and disliking close association with others. However, this aloof exterior masks a surprisingly strong sense of justice and personal integrity. This principle is so central to his character that he was the sole member of his dorm to refuse participation in the scheme to sabotage the other teams during the Magical Shift (Spelldrive) tournament, effectively going against his own house for the sake of fairness. He is also notably intelligent and observant; for example, he was able to deduce Azul Ashengrotto's true merform just from Leona's nickname "octo-punk" and quickly understood the mechanics of Floyd Leech's unique magic during a confrontation.

Jack's primary motivation is self-improvement and the pursuit of strength, though he strictly adheres to a personal hierarchy of power and dislikes being indebted to anyone. He holds a deep respect for those he considers powerful and principled, most notably Leona Kingscholar. Jack was inspired to attend Night Raven College after witnessing Leona's skill in a Spelldrive tournament years prior. However, he is not blindly loyal; he strongly disapproves of Leona's underhanded tactics during the tournament incident, believing Leona is capable of winning fairly through genuine effort. He respects Riddle Rosehearts immensely for his achievements and efforts as a housewarden, and he has a profound admiration for Ruggie Bucchi, whose loyalty to Leona he finds impressive. Jack often seeks Ruggie's approval and mentorship, even going so far as to climb trees to retrieve a stolen necklace for him.

He shares a friendly and mutually respectful relationship with his classmate Epel Felmier, as they are often seen together and speak positively of one another, though they do have a light-hearted disagreement over whether apples or pears are better. Jack also has a significant pre-college connection to Vil Schoenheit; they are from the same hometown, and Jack once defended a young Vil from bullies who targeted him for playing a villain on a television drama. In the present, they maintain a friendly relationship and often go on morning jogs together.

While he is not a character who seeks out teamwork, Jack proves himself to be reliable and principled when the situation demands it, such as when he offered to help the Ramshackle Dorm's prefect after they were evicted by Azul. His notable abilities include a sharp memory and keen senses. His unique magic is called "Unleash Beast." Unlike standard transformation magic which typically requires a potion, Jack's signature spell allows him to physically transform into a huge white wolf, a feat considered to be extremely advanced and special by his professor, Crewel.