|Appears in:||Fate/Prototype: Fragments of Blue and Silver|
He was called "Caesar", who was the strongest in the continent. His title was the "Sword Emperor".
He has dark red hair, purple eyes and a build similar to King Arthur.
He has a violent personality shown through his ruthlessness, and his enjoyment of battle and blood-shed. He is also the epitome of arrogance due to his belief that having been born a king he has the right to do anything he pleases and views his rule as being like a god on earth.
Fate/Prototype: Fragments of Blue and SilverEdit
The battle between Lucius and Arthur is detailed in a flashback.
He has physical abilities comparable to a magical beast and he wields the demon sword, Florent.