You were in a cave when you stumbled across a large, dark sword that seemed to be the Master Sword's evil version, in a way. The gem on the hilt appeared to double as an eye, as it followed your every move in a predatory manner. You had reason to believe that you had stumbled into the cave of Ghirahim, the Demon Lord. It's been thousands of years, and yet he's still around... and he definitely isn't happy that there's an intruder in his cave.