Deathcalibur

Deathcalibur (デスカリバー) is the primary weapon of the Black Knight in Sonic and the Black Knight. It can fire magical energy bolts, transport King Arthur, and summon creatures from the Underworld. In many respects, it can be considered the polar opposite of Caliburn/Excalibur. Its origins are unknown. It disappeared along with King Arthur when Sonic killed him. It is indicated by Sir Gawain that he had never seen Excalibur, so it can be assumed that this sword is not a transformed Excalibur.