Z.W.E.I. is a playable combatant introduced in Soul Calibur V. He is a werewolf, and wields a three-handled sword. He can also summon a wolf spirit in combat named E.I.N. (In German, "zwei" is the word for "two," and "ein" means "one.") Z.W.E.I. is an ally of Siegfried and Viola, and is the one that takes Patroklos to meet Siegfried. He also bears a grudge against Nightmare and seeks to defeat him in battle.
During the story mode of Soul Calibur V, Z.W.E.I. eventually comes face to face with Nightmare. The two battle and Z.W.E.I. is victorious, but the battle leaves him distracted, and Pyrrha, possessed by Soul Edge's corruption, runs him through. It is not yet known if Z.W.E.I. survived the encounter.