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.
Operation Han-Gyaku-Sei Million Arthur
The sacred sword "Excalibur". A sword that was created to judge a person's ability to be king of England. Those whom the sword accepts will be called "Arthur" and will obtain great power. However, there was not a single Arthur, but many more. Due to this massive creation of legendary humans, the world and its history began to be distorted. Now, with the aim of restoring the history of the world to its original course, six Arthur, a master of the sword, a fighter, a sniper, a puncher, an alchemist and a shooter, will go to this place, England. Their mission is to defeat all those who have managed to obtain a power from the sacred sword Excalibur and who are distorting the world, which are around a million people.