User blog:Bowserdude/DB Headcanons Pt. 2

Mario VS Sonic
This isn't very hard. They were both very aware of their rivalry, and had decided to settle the score.

Luigi VS Tails
Luigi, having heard what had happened to Mario, was out for revenge. However, he was scared that if he fought Sonic, the same thing would happen to him. And he certainly didn't want his back shredded open. So, he decided for the next best thing. He went for Tails. Too bad it didn't exactly go so well for him.

Eggman VS Wily
Sonic and Mega Man had told their respective villains about the other, hoping that they would destroy each other in the process. The two doctors had then met up with their armies, and proceeded to fight. Pretty much no one saw what happened coming, and it took the combined efforts of Sonic and Mega Man to destroy the Roboenza-infected Metal Overlord.

Batman VS Spiderman
Spiderman was still holding a grudge against Batman for not letting him into the Justice League, and had arranged for them to fight. Batman simply agreed because he had nothing better to do, and it would get Spidey off his back.