It would be a big machine similiar to a vacuum cleaner with a hose. The main unit has a big smiley face on it like this . Then you point the hose at your enemy and it sucks out all the hate, all the vitriol and replaces them with all the good qualities you have come to expect.
It doesn't have a high offense value, nor defense...but it transforms the heart of the enemy and turns them in turn in to kind, loving, classy, people. Then the game ends with us all being friends and the song Kum-bay-ya plays in the background.