Oriana Thomson (オリアナ＝トムソン Oriana Tomuson?) is character introduced in Toaru Majutsu no Index. She is a magician that was born in England and works as a mercenary. A woman who truly wants to help people, she originally, served as antagonistic character during the Daihaseisai. After her capture, she brokers a deal with Necessarius and works for them in order to help people during the chaos created by the increasing tensions between Academy City and the Roman Catholic Church.