|Nastassja Sergeyevna Tolstaya|
|Romaji||Nasutāsha Serugeivuna Torusutaya|
|Anime||G Episode 1|
|Game||Senki Zesshō Symphogear XD Unlimited|
Nastassja Sergeyevna Tolstaya (ナスターシャ・セルゲイヴナ・トルスタヤ Nasutāsha Serugeivuna Torusutaya?), more commonly known as Professor Nastassja (ナスターシャ教授 Nasutāsha-kyouju?) or Mom (マム Mamu?) by Maria, Shirabe, and Kirika, was an heretical engineer who supports the operations of Maria's team.
Nastassja Sergeyevna Tolstaya is a Russian name.
Nastassja — has its origins from the Greek "Anastasia", although it is a popular name in Russia. The abbreviation of the name "Nastassja" is "Nastea". The name means "resurrection".
Sergeyevna — is her patronymic which indicates that her father's name is Sergey/Serghei.
Tolstaya — is a Russian surname. The male form of this is "Tolstoy".
Professor Nastassja was an older woman with indigo hair and lilac eyes. She weared a black eye-patch over her right eye and is confined to a wheel chair. She was always seen wearing a long black dress over a lilac turtlenecked shirt.
Professor Nastassja was seen as a motherly figure to the girls of Maria's team and even Maria herself. However even though she looked upon them with kind eyes she also intentionally treats them very strictly in order to keep them focused on their difficult mission.
AXZ reveals that in the past, Nastassja would abuse the Receptor Children by striking them with a riding crop as punishment for disobedience. However, it was revealed that all those abuse was actually a tough love from Nastassja and that she felt remorseful deep down since she did those to push the Receptor Children of not giving up and continue to work hard.
Prior to the events of G, Nastassja was a member of the F.I.S. who trained Maria Cadenzavna Eve, Serena Cadenzavna Eve, Kirika Akatsuki, and Shirabe Tsukuyomi. At an unknown point, she began collaborating with John Wayne Vercingetorix.
After the events of the Lunar Attack, one segment of information regarding the sacred relics was released to the public, however the knowledge that Nastassja holds is far greater than that.