The Split Dark Sword, or even War/Broken War.
I question it, because of the Vitrica, Tatsu, and Paracesis. The added abilities are nice, however, I don't like the whole 2H aspect. It seems that special weapons released via story missions are 2H. Couldn't we get story weapons of this type that could have a counter part via either a special mod, as the SDS, or an entirely new weapon of similar type with War/Broken War?