A design from the early drafts of Fate/stay night back when Saber was going to be a male character. He was redesigned for Fate/Prototype and Fate/Prototype: Fragments of Blue and Silver as Prototype Saber.
The name "Saver" comes from a typo in Character Material, the official TYPE-MOON book in which this design appeared (see post #65859).
Often seen with Sajou Ayaka.
Nobody here but us chickens!