I'm pretty sure the vile weapons belonged to Ausar. Archivist talked about the Vaut of Tears being the home to "the most evil and vile to befall this world" and when you defeat Radriar, he says "you were always a vile plotting wretch, Ausar..."
And since all the vile weapons possess dark energy, it gives us more proof that Ausar was evil like all the other deathless. Maybe the dark equipment found in the first Infinity Blade was hinting to this? When you entered BG you were essentially returning to Aursar's past; hence the dark equipment.