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.
Soulcalibur
In 1563, a Spanish pirate, Cervantes de Leon stole Soul Edge from a dealer's ship, but gradually became corrupted by its spirit until it devoured his soul, influencing him to terrorize the world for twenty years. This terror made several warriors to venture out and stop him, including a female ninja, Taki, who wanted to destroy Soul Edge for having corrupted her master, and a German rebel, Siegfried Schtauffen, who desperately wanted to blame someone for the accidental murder of his father. Eventually, a Greek warrior, Sophitia Alexandra, confronted and managed to destroy one of Cervantes' blades, but the battle was eventually ended by Taki, who managed to slay Cervantes. Siegfried then came to check Soul Edge, but he became possessed by the release of the "Evil Seed" and turned into the monstrous Nightmare. The Evil Seed event had major impact to the world, including several people going insane, and Nightmare replaced Cervantes in terrorizing the world, wanting to recover the lost Soul Edge fragments. Three years later, Nightmare had prepared for the ritual to complete Soul Edge, but three warriors from Asia, Chai Xianghua, Kilik, and Maxi stormed his castle, the Ostrheinsburg and managed to defeat Nightmare, with Soul Edge's spirit (Inferno) being shattered by Xianghua's blade, which was revealed to be the lost Soul Calibur. Though Siegfried temporarily regained his sanity, he became possessed again shortly after, as did Soul Calibur, which succumbed to the darkness of Inferno.