TV-Series
Description
Caules Forvedge Yggdmillennia is a young man of eighteen years, born on March 23rd, who stands at 172 centimeters and weighs 63 kilograms. As a member of the Forvedge family, part of the larger Yggdmillennia coalition of magus lineages, he was brought into the world for a very specific and pragmatic purpose: to serve as a spare heir and caretaker for his older sister, Fiore. While Fiore was born with exceptional, once-in-a-century quality Magic Circuits, a physical disability affecting her legs caused the family head to doubt her viability as a sole successor. Thus, Caules was born. However, a second miracle did not occur; his own magical aptitude was profoundly mediocre, a fact that seemed to embody the Forvedge family's decline. His father ultimately decided that Fiore, despite her condition, would be the heir, and Caules was commanded to support her.

Personality-wise, Caules carries himself with the air of a resigned and slightly cynical young man. He never harbored grand ambitions as a magus, viewing magecraft not as a life-defining pursuit but as an accessory to a normal human life. This pragmatic, almost detached outlook is paired with a warm and humane nature. He is notably more grounded in the modern world than his peers, possessing a wealth of contemporary knowledge and interests such as computers, video games, and manga, and he was the one who introduced his magically focused sister to the use of a cell phone. Despite his easygoing front, he possesses a sharp analytical mind and a core of cold realism. The narrative notes that were he and his sister to ever face each other in a standard Holy Grail War, while Fiore might be plunged into despair after killing him, Caules would experience despair and then kill her without hesitation. In this specific sense, his consciousness as a magus is arguably stronger than his more talented sister's.

Caules's involvement in the Great Holy Grail War of Fate/Apocrypha is entirely circumstantial and unwelcome. He had been considering abandoning the path of a magus altogether when he accompanied Fiore to Romania simply as her backup. Upon their arrival, Command Seals manifested on his hand, forcing him to participate. With no personal wish for the Grail, his primary motivation became survival, specifically the survival of himself and his sister. He is the Master of Berserker of Black, the creature known as Frankenstein's Monster. His catalyst for the summoning was a copy of the original blueprints for the "perfect human," purchased for him by Fiore. Despite the handicap of having a Berserker who cannot speak, he quickly works to understand her abilities, limitations, and even her unspoken emotional state, demonstrating a keen strategic mind. He is considerate of her feelings in a way unusual for a Master, avoiding forcing her into spiritual form if it might upset her.

His most significant relationship is, of course, with his sister, Fiore. While he is resigned to his role as her caretaker and secondary support, there is a genuine bond of familial responsibility between them, and much of his actions in the war are calculated to ensure her safety. Another key relationship, though fleeting, is with his Servant, Berserker. Though they cannot hold a conversation, a poignant and mutual understanding develops between them over the course of the war, with Caules showing her a level of respect and kindness she likely never experienced in her short life. Following the war, Caules enters the Clock Tower's El-Melloi Classroom as a hostage in all but name to secure pardons for his clan. There, he forms another pivotal bond with his new teacher, Lord El-Melloi II, who recognizes Caules's latent talent for a branch of magecraft entirely different from his family's.

Throughout the narrative, Caules undergoes a subtle but definite development. He begins as a young man who has half-resigned himself to a life of mediocrity, but the trials of the war and his connection with Berserker seem to draw him out of his passivity. After the war, rather than retreating from the world of magic, he chooses to explore a new path, showing an adaptability that belies his average circuits. In the world of Lord El-Melloi II's Case Files, he finds his specialty in electrical magecraft, a field he has far more talent for than his family's spiritual evocation.

In terms of abilities, Caules is consistently described as a low-ranking magus with poor-quality Magic Circuits in both quantity and quality, rated D and E respectively. His family's specialty is Spiritual Evocation, a field in which he has minimal talent. He is, however, capable of summoning and controlling low-class spirits, insects, and animals for use as familiars. He also possesses knowledge of basic healing magecraft and can deploy Bounded Fields. His true proficiency, which only becomes apparent later on, lies in Bio-Electricity or Electrical Magecraft. Under the tutelage of Lord El-Melloi II, he develops spells such as Crafted Tree: Hanged Thunder, which unleashes countless branching bolts of lightning, and he wields a Mystic Code called the Primeval Battery, which allows him to manipulate bioelectric currents to accelerate healing or activate magical energy.