Great picture, however, its clearly drawn by a female. A double edged curved sword is simply, well, stupid. And they have never been made in the real world. The curve was for greater cutting power, which obviously would only be on one side, while the double edged blade gave the advantage of more versatility.
The double edge was a european design while the curved was eastern, from arabians to the asian cultures, who though also had their own variations of double edged blades.
But yeah! Know you know it, and wont make that mistake again ^_^