"The heavier the weight, the greater the power" No. Swords are precision weapons, not big smash sticks, force equalizers that are designed to do as much damage as possible with minimal force. Regarding power, kinetic energy = mass * velocity^2. Speed is more important than mass.
It would be useless, a sword is no use if you can't move it quickly, ask any competent fencer. It's arguably more useless as a mace; one-handed maces are about shortsword length and weigh about the same as one-handed swords, if a bit more, only with the opposite weight distribution. Whereas the...