Saber is a character that appears in many parts of the Fate series including Fate Zero and Fate Stay Night. For anyone that is not familiar with the Fate series, it is based around an event known as the Holy Grail War (well Zero and Stay Night are, I haven’t looked much deeper than that yet).
The Holy Grail War is a competition founded by the Matou, Einzbern and Tosaka families with the aim being to claim the Holy Grail which can only be obtained by the winning master and servant. By winning, the Holy Grail will grant one wish for each of the two members in the team. The masters are seven mages from different families and they are required to summon a servant/heroic spirit before the start of the war. Their heroic spirit will be summoned from a particular class, the classes include Saber, Lancer, Archer, Assassin, Caster, Berserker and Rider.
Saber’s true identity is that of Artoria Pendragon (otherwise known as King Arthur), meaning that in her previous life she was born male although she does not care for gender and is usually referred to under her class name. She only sees herself as a tool for her master and her sole purpose is to win the Holy Grail but she will not abandon her chivalry to do so, she always tries to conduct a fair battle when facing opponents.
As well as chivalrous, Saber is also loyal, strong and independent. She appears cold at times but that is because she is focusing her goal of securing the Grail’s wish for her master and herself. We learn that her wish, should she obtain the grail is to undo her rule of Britain so that someone more suitable can take her place, as she felt a great sense of self doubt and loathing over her time as king especially when it came to the actions she took trying to save her people. She blames herself for the destruction of her kingdom and feels immense guilt over it but she eventually has to come to turns that her wish isn’t possible.
Saber’s wish has often been criticised as being selfish but I personally think it reflects a kind, although foolish, nature from her as she is willing to sacrifice herself to help her people. I think she was a pretty good ruler if she’s prepared to go that far for everyone but I do wish she would give her own wellbeing a bit more thought.