Mira Naigus

Mira Naigus (ミーラナイグス, Mīra Naigusu; FUNimation "Mila Naigus"), known by the alias Demon Knife (魔ナイフ, Ma Naifu), is the Demon Weapon partner of Sid Barrett and replaces Medusa as the Interim School Nurse after her defection from the DWMA.[4] She also has involvement with the DWMA Intelligence Agency and took command after Sid's death and before his revival as a zombie and acts as one of the teachers within the DWMA.