Miyamoto Musashi (宮本武蔵?) is the male version from the Greater History of Man, in contrast to the female version from a pruned word-line.
The Musashi who appears in Shimousa is a still living Musashi who is sickly and dying years before his normal date of death. Sitting alone in a cave, he is awaiting his final opponent.
As a Servant, one Noble Phantasm he could possess is Oar Wooden Sword.