Stiyl Magnus (ステイルマグヌス Suteiru Magunusu) is a magician affiliated with the Church of Necessary Evil (Necessarius), and was Index's partner two years prior to the start of Toaru Majutsu no Index. He is a formidable magician who uses brand magic and runes and is partnered with the Saint Kanzaki Kaori. He is the first magician and antagonist that Kamijou Touma confronts in the series, introducing himself as an enemy of Index.
He is currently assisting Archbishop Laura Stuart of the Anglican Church, knowing full well that she was the one who lied to him and Kaori about the true condition...