Excalibur
Geoffrey of Monmouth, in his "Historia Regum Britanniae" ("The History of the Kings of Britain", c. 1136), Latinised the name of Arthur's sword as "Caliburnus" (potentially influenced by the Medieval Latin spelling "calibs" of Classical Latin "chalybs", from Greek "chályps" ["χάλυψ"] "steel"). Most Celticists consider Geoffrey's "Caliburnus" to be derivative of a lost Old Welsh text in which "bwlch" (Old Welsh "bulc[h]") had not yet been lenited to "fwlch" (Middle Welsh "vwlch" or "uwlch"). In the late 15th/early 16th-century Middle Cornish play "Beunans Ke", Arthur's sword is called "Calesvol", which is etymologically an exact Middle Cornish cognate of the Welsh "Caledfwlch". It is unclear if the name was borrowed from the Welsh (if so, it must have been an early loan, for phonological reasons), or represents an early, pan-Brittonic traditional name for Arthur's sword.
Excalibur: Morgana's Revenge
The game's story expands on the legend of King Arthur and involves the Sword of Power, Excalibur; the wizard Merlin; the sorceress Morgana; and the future United Earth Federation (UEF). The story takes places across three time periods. According to the game, Morgana uses the Charm of Making to imprison Merlin in ice during the fall of Arthur's kingdom. Merlin then disappears from Camelot in an electrical storm during the battle for Camelot.