It's a hot wire cutter, you can buy it at stores for things like saws. Or if you are diy u can take an old wire made of something with a high melting point and torch it until it is really hot. Hope this helps!
Just wanted to point out in game 1, Adam played wyvern guard, it left his hand, then he added it back, and rode for turn. When opponent miss played by trying to perfect defend the rear guard, Adam made him use the PD, and ditch the card.