To know "Red" is the servant of class to know of Kairi Sisigou of the Red Faction in the Great War of the Holy Grail of Fate / Apocrypha. Saber is also known as Mo-san in Koha-Ace. She can be invoked as a servant by the Protagonist in Fate / Grand Order.Saber's real name is Mordred, the Knight of Betrayal, and the "son" of King Arthur. But in truth it is a woman raised as a secret male heir. She is considered a "rare villain" who had stained a glorious legend at the end of her life.
Mordred was born from the union between Arturia and his sister Morgan le fay through unorthodox circumstances. Arturia at that time was a pseudo male by the influence of Merlin's magic to produce an heir, was enchanted by Morgan who extracted with his magic his sperm, which when combined with his ovule developed a homunculus clone of Arturia. Due to its homunculus condition, its growth was rapid compared to a normal human and its life time was short. She was raised in secret and asked to hide her face and obey the King until the time comes.
