Vittorio Cassera

Vittorio Cassera (ビットリオ＝カゼラ) is a character introduced in Toaru Majutsu no Index, as a member of the Thirteen Knights of the Roman Catholic Church ordered to hunt down Aureolus Izzard.

Personality
He is shown to be dedicated to his duty as knight of the Roman Catholic Church, and would willingly sacrifice the lives of thousands in order to bring down one man. However, when Touma meets him, he warns him of the impending destruction of Misawa Cram School. He is probably also responsible for using a barrier to stave off civilians such as Touma from entering the area where the bombardment of Misawa Cram School.

Deep Blood Arc

 * Main article: Deep Blood Arc

Touma meets Vittorio after he accidentally releases himself from Aureolus memory erasure. Here, along with the other knights, surround the building of Misawa Cram School in order to bombard with the Gregorian Chant.

Despite Touma's pleadings regarding the amount of blood they will spill if they attack, Vittorio goes on with his plans and bombards the school with the Gregorian Chant. The attack is in vain however, as Aureolus' Ars Magna manages to reverse the effects of the bombardment, and injures Vittorio as well.

After the end of the end of the volume, Stiyl states that the only casualty was Parsifal of the knights, meaning that Vittorio is still alive, although his whereabouts remain unknown.

Abilities
Vittorio's is apparently the Lancelot of their unit and seemingly the leader, as they are all named after the members of the King Arthur's Knights of the Round Table. Naturally, Vittorio exhibits several abilities displayed by a knight of the Roman Catholic Church. His most notable ability however, it the ability to use the true Gregorian Chant along with other knights, which follow his command.

Trivia

 * A knight appears in the 8th episode of the anime adaptation of the Deep Blood Arc. Here, a knight recites the same spell Vittorio recites in order to bombard the Gregorian Chant on Misawa Cram School. The knight is voiced by Yoshihisa Kawahara