Nikolaus Nikolaus; ニコラウス; Nicholas
Age
Gender Male
Blood Type
Birthday
Family structure
Spoiler　Father: Karstedt 　 Mother: Trudeliede (father's second wife) 　 Older half-brother: Eckhart 　 Older half-brother: Lamprecht 　 Older half-brother: Cornelius 　 Older half-sister: Rozemyne 　 Paternal relatives 　 Great-grandfather: Aub Ehrenfest (fifth generation) 　 Great-grandfather: former Giebe Leisegang (Bonifatius's first wife's father) 　 Grandfather: Bonifatius 　 Uncle: Traugott's father 　　　 Cousin: Traugott
Age related
Spoiler　Grade difference with Rozemyne: -3 　 Birth season: other than winter

He has bright maroon hair and light blue eyes.