That Lavos pic is absolutely freaking awesome. But knowing Lavos' level of technology, he probably would be using a lightsaber, or Force forbid something even cooler. (Is it possible to be cooler than a lightsaber?)
Maybe. Or yet again, maybe the sword just has, what is it called, coreoilis weave? Needless to say, it could then stand even against a light-saber. In KOTORII the Sith Sword, that double bladed thing, was nearly as powerful as my lightsaber for a very long while. Furthermore, a sword may be magical, enchanted never to break (Anduril), or to deal death to whatever its edge bites (Anglachel), which is not the case with lightsabers. Plus, as a matter of preferences, I far prefer the look of steel and cross-guards and pommels over that of a lightsaber. They're neat, but nothing beats the weight of a 2lb sound flourished in your hand.