In an attempt to bring peace to the world for the new year heroes talked villians into getting together to negotiate a treaty. It took several days to work out the terms of the truce. The heroes worried that the villians wouldn't stick to it. Villians weren't known for keeping their word. So their had to be something that made them hesitate and reconsider their actions. So it was suggested that each hero and villian give one child to be married to the other side. This way the scales would be balanced. No archnemesis would be bound. And no one would know who was marrying who until their wedding day.