Sukeroku

Sukeroku is a character appearing in Fate/Grand Order.

Background
Sukeroku is an oni residing in a dream-like world. He was originally a swordsman in Musashi's original world, having faced her shortly after she left her village. She slayed him, and his grudges turned him into an oni.

Fate/Grand Order
Sukeroku appears as a cowardly oni in Musashi's trial quest, eventually regaining his memories. He attempts to kill her again, but is defeated.