More onto the topic though; I do believe that the Weapons would make a formidable oppenent as a human. They'll be a lot faster for one, and with their devastating power combined with that new speed, they really would be almost unstoppable.
It would be extremely interesting if you could get one of them into your own party. The more I think about getting one in your party the more I want it to happen. Think of their Limit Breaks. Their Limits would be amazing. But, what would you call them all? And, what would they do?
In answer to the title of the topic; If the Weapons were to take the shape of a human, it would be the end. There would be nothing you could do, especially if they had some sort of cloaking device that was to disguise them as everyday civillians. You couldn't tell a civillian from a Weapon.
So, all in all, it would be
very interesting if they were to take the shape of a human.