Styl Magnus is a magician of Necessarius, the Church of Necessary Evil within the English Church. He stands 200 centimeters tall with a slender build and shoulder-length red hair, which is blond dyed red. A barcode tattoo sits under his right eye, and he wears large hoop earrings and silver rings on all ten fingers. He is almost always seen in a black priest's robe, accompanied by a strong perfume scent and the constant presence of a cigarette. Despite his mature appearance, he is 14 years old. His physical weakness is a direct side effect of his magic, which consumes immense energy and leaves his body frailer than average. His personality is stern and short-tempered, marked by a disciplined exterior that hides a core of kindness and a fierce dedication to protecting those close to him, especially Index Librorum Prohibitorum. He maintains loyalty to Necessarius but will defy orders that clash with his personal justice. He often exhibits a cynical attitude, particularly toward Academy City for its restrictions on cigarette sales to minors. His interactions with Kamijou Touma are frequently irritated, yet underpinned by respect. His heavy smoking is a defining habit, and he regularly comments on his reliance on nicotine. Two years before the main events, Stiyl was assigned as Index’s protector alongside Kanzaki Kaori. They traveled with her to copy the grimoires in her mind and accompanied her to the Vatican for the implantation of additional books, forming a close friendship. The Church later informed them that Index’s brain had no space for new memories due to the 103,000 grimoires, requiring an annual memory erasure to save her life. After witnessing her physical decline and participating in the traumatic erasure, they attempted to rebuild their friendship. To spare her the pain of future losses, they deliberately let her perceive them as enemies, causing her to flee to Academy City with them in pursuit. It was after her memory was erased that Stiyl acquired his barcode tattoo, ear piercings, and rings. His greatest regret is failing to save Index without the loss of her memories. Upon learning the Church had deceived them—human brains cannot die from information overload—he disobeyed orders to capture her, allowing her to live freely with Touma. He remains committed to protecting her from the shadows, often operating around Academy City for this purpose, though she remembers nothing of their past. He continues to undertake missions for Necessarius, even under Laura Stuart, who orchestrated the deception. As a magician, Stiyl specializes in rune and fire magic. His magic name is Fortis931, meaning "I prove why my name is the strongest here." A recognized genius, he fully analyzed the standard 24-rune alphabet and created six new rune characters. He casts spells using pre-made, laminated rune cards, an upgrade from paper after his ink was once washed away. These cards are waterproof and fire-resistant. His fire magic is extensive. He commonly wields a flame sword burning at 3000 degrees Celsius. A variation, Squeamish Bloody Rood or Crimson Cross for Vampire Killing, creates two flame swords, sometimes red and bluish-white, to scissor opponents. His signature spell is Innocentius, the Witch Hunter King, a flaming giant also burning at 3000 degrees Celsius. It has automatic homing and can regenerate indefinitely within its rune field. Beyond attacks, he uses fire and heat to create mirages and visual illusions, employing up to three layers of dummy deceptions. He can detect hidden individuals through their body heat and has demonstrated the ability to heal burns, once using this skill to alter facial features by burning and healing tissue. His cigarette smoke is incorporated into his magic, forming symbolic patterns to transmit messages or, with rune cards, to analyze and diagnose mental conditions by connecting his mind to another’s. On one documented mission, he was dispatched to Academy City to deal with a betrayer. He collaborated with Theodosia Electra, a magician who uses Norse magic and matches, only to discover she was an accomplice of the primary target, Patricia Birdway. Patricia was a non-magician girl whose sister led the Dawn-Colored Sunlight magic cabal. The official mission was to capture Patricia to obtain a key stone for deciphering the Alaska Runes, an act Stiyl found unjust. During the mission, Patricia was attacked with a mental spell, and Stiyl used a cigarette and rune cards to perform a diagnostic spell on her condition. He faced an enemy wielding Lævateinn, a sword that could set his own flames on fire and burn anything without a trace. To protect Patricia and disrupt the enemy’s plan, which also required an item called Donati's Horoscope from Academy City, Stiyl split from Theodosia and pursued the horoscope. His interactions are defined by a complex relationship with Kamijou Touma, oscillating between rivalry and reluctant cooperation over Index’s well-being. His dynamic with his former partner, Kanzaki Kaori, is one of shared history and mutual respect forged through their failure and guilt regarding Index. He also has noted interactions with Komoe Tsukuyomi, a teacher in Academy City, who often scolds him for his smoking, highlighting the contrast between his mature appearance and his actual age.