The answer would depend on the type of sword. An epee or foil would be different from a cutlass, saber or broadsword. A concern is that the change in the weight would require a change in the style of fighting as well. My choice would be a straight double edged (true sword). Not having a clue about how to make a sword I would suggest to a swordsmith that the core of the sword be a mostly hollow honeycomb design with a Graphene/steel mix to reduce the weight and engineered to increase ductility. Then I would wrap the core with a Graphene/steel coat. The main objective is to move the point of balance to the hand while providing an edge that is more durable. I would love to see a sword like this maybe Angel Sword would take this challenge on.