Chevalier d'Eon

Chevalier d'Éon is a fate grand order character. d'Éon was a famous french spy from the 18th to 19th century. said to be incredibly so beautiful that they couldn't tell if d'Éon was a male or female. So the throne of heroes made d'Éon non gender and it's gender depends on master. if d'Éon master sees d'Éon on a male, then he becomes male, or if they see it as a woman, then d'Éon becomes a female.