References in Heavensward

[Starmorning]

I heard Dark Knight is based on Guts from the Berserk manga.

(PS darn if only Berserk Manga can update decently again )

http://finalfantasy.wikia.com/wiki/Dark_Knight

The dark knight class has been in the franchise since 2. The dark knight itself might be a callback to the black knight of Arthurian legend.