Erisviel von Einzbern
A slender and petite teenage girl, appearing roughly 14 or 15 years of age. She has snowy white hair tied up in twintails and her eyes are heterochromic, with one bright blue and the other crimson red.
The mysterious girl who called Artyom and Kazumi to Einzbern Castle and provided them with the catalysts to summon their Servants. Little is known about her publicly, but she seems to be both energetic and shy, earnest in her dealings with others, and modest when receiving praise. Unlike many mages, she shows a great interest in technology and computers and appears to be a master hacker, as she has demonstrated the ability to hide herself behind multiple proxies and hack into sophisticated smartphones and other devices. As an Einzbern magus, she likely possesses great talent in magecraft as well, though she has yet to directly demonstrate such.