Sword?

While I was playing my first run I remember that I had Amiri with some kind of a Great Sword (? It was a double handed sword, it was black with some kind of thorns that deal a good amount of damage but damage Amiri as well for a little bit of extra damage. I remember fighting Armag with it but now in my second run I haven't found it (And I was following some guides) so I thought probably was Armag's sword but after reading what Armag's word do and look I think it's not that one. I don't know if I'm wrong and confusing it with other sword but I feel bad because it was a great sword actually