My to-go Glamour for everything. It dosen't stand out, but is solid.
Gordian Greatsword isn't needed, you can fit any Weapon that has a regal/knightly/defined theme to it, my choices for Dark knight would be : Claymore of the Round, Edge of the Goddess or even any Leveling greatsword that looks simple (i.e. Molybdenium Longblade)