Ascot is initially introduced as a young child who serves as one of the followers of the antagonist Zagato. His most defining trait is his rare ability as a Palu, a summoner who can call forth monsters from another realm. These creatures, which he considers his only friends, are large and often monstrous in appearance, yet they possess no inherent ill will. Despite their peaceful nature, the people of Cephiro feared them, leading to Ascot and his summoned companions being driven away from every place they tried to call home. Homeless and isolated, Ascot was a lonely outcast until Zagato offered him and his monsters a place to stay in exchange for his loyalty and service.

Driven by a deep-seated hatred born from rejection and a selfish desire to protect his only friends, Ascot acted as an antagonist to the Magic Knights. His personality in this early stage is marked by arrogance and a cruel streak, viewing the knights with dismissive mockery. He is consumed by a childish self-centeredness, seeing his own pain as justification for his actions without considering the harm he causes others. This is most evident when he uses his summoned creatures to attack the knights, causing them pain in battle and, in the anime adaptation, destroying the home of the fencer Presea, an act that leads to her death.

His role in the story changes fundamentally following a confrontation with the Magic Knight Umi Ryuzaki. After a battle in which Ascot forces his monsters to fight for him, Umi slaps him and delivers a harsh lecture, accusing him of being a bad friend for making his companions fight and suffer on his behalf. She teaches him that true friendship requires one to stand up for and protect their friends, not hide behind them. This powerful rebuke shatters Ascot's worldview and causes a complete change of heart. He forsakes his allegiance to Zagato and learns the true meaning of friendship, starting his journey toward redemption.

His key relationships are central to his development. His bond with his summoned monsters remains the most important constant in his life. He also forms a sibling-like relationship with Caldina, another of Zagato's former servants, with the two caring for and teasing each other. His relationship with Umi is the most transformative. Inspired by her words and actions, he develops a deep admiration and love for her. This feeling is so powerful that by the time of the second story arc, his will to be older and more worthy of her has physically manifested, causing him to rapidly age into a tall, handsome young man.

His development is marked by this profound physical and emotional maturation. In his younger form, he is a bitter antagonist, but he grows into a calm, sweet, and devoted ally to the Magic Knights. While he retains his summoning powers, he seeks out training from the master mage Clef to learn other spells, specifically to avoid using his monster friends as living weapons in combat. His unrequited love for Umi persists, and though he confesses his feelings, he accepts her response that she cares for him as a dear friend and continues to selflessly protect her and fight for the future of Cephiro.

Regarding his abilities, Ascot's primary power is summoning. He can call forth a variety of huge creatures, each with unique powers such as flight, burrowing, breathing acid or flames, and creating whirlwinds. He is also capable of traveling on a small, flying platform of rock. After his redemption, he supplements his summoning with newly learned magic, demonstrating a commitment to growing stronger through his own power rather than relying solely on his summoned friends.