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.
Black Knight (Dane Whitman)
Whitman reappeared in "New Excalibur" in the mid-2000s. He has opened up a museum in England chronicling the Black Knights that have existed throughout history. Whitman recently learned that Sir Percy was not the original Black Knight, but that eight men had held the Ebony Blade prior. The Ebony Blade however corrupted these men, and Sir Percy was deemed the only one noble enough to wield the Blade. Also at this time, Merlin told Whitman that he must not destroy the Blade as he had previously been told to do. It is not clear whether he has access to his Avalonian equipment at present. In "New Excalibur", Whitman was invited to join the team but after the second adventure with them he refuses as he believes that his Ebony Blade is not the real one and needs to find the original.