Siegfried Schtauffen (シーグフリード・シュタウフェン Shīgufurīdo Shutaufen?) is a fictional character designed for the Soul Series of fighting games. Siegfried made his first appearance in Soul Edge and has returned for Soul Calibur, Soul Calibur III and Soul Calibur IV. He can also be seen in Soul Calibur II as an unlockable costume for his temporary alter-ego, Nightmare.