Forgefire 07

Through the carefully defined blows of their hammers and the old words sung, just as they'd been carved into the stone of the ruins, they set the viscous metal into shape. Each one was was unique in it's guidance and design. It was from the ruins around his forge that Thiskaar learned his craft and it was the same walls, and through his tutelage, that Kibal learned as well. 

Not only must the living metal be shaped but then it must be bound into that shape with cold metals which allows the user to safely wield the swords. Great care must still be taken in using them as the blades will melt through most stone and metal in the known world. While the user's hands are protected at the hilt even from exposed parts of the living metal, the rest of the blade is live and naked. Even experienced swordsmen have lost fingers in mishandling these blades.