Nightmare
Siegfried Schtauffen from the Soul Edge/Calibur series after gripping the cursed hilt of Soul Edge.  As Siegfried, carries a massive Zweihander named Faust, or another named Requiem.  Probably the best character in the SE/C series.  Appears in full platemail armor in SE, without helm in SC/SCII, or as Nightmare, in full plate with his right arm exposed, looking as though it were torn off of a demon and surgically placed over his own arm.
"I will show you...the GREATEST nightmare!"