aleister crowley (toaru majutsu no index)
The leader and founder of Academy City in Toaru Majutsu no Index and its spin-off Toaru Kagaku no Railgun. In the series, Aleister Crowley was the greatest magician to ever have lived but turned his back on magic to study science. He is essentially the man behind the plot.
His namesake was an English occultist in the last 19th and early 20th century and one of the more well-known members of the Hermetic Order of the Golden Dawn. He is considered the coiner of the phrase "do as thou wilt shall be the whole of the law," which is paraphrased from his book Liber AL vel Legis. His syncretism of Hermeticism, yoga and other Eastern spiritualism, and Egyptian mythology combined with his prolific writing has made him hugely influential in modern occult and neo-pagan movements.