It allllllllllllllllllllmost makes me think Sonic could beat Mario.
If only we could get that as a bonus match after the true contest final. I had an idea of getting some matches involving only the Noble Nine that have never happened in a 1v1 match. There's only 6 potential match combinations meeting those requirements.
Cloud/Mega Man Crono/Samus Crono/Sephiroth Mario/Sonic Mega Man/Samus Sephiroth/Sonic
That's all of the remaining Noble Nine match-ups which have not happened in a 1v1 match. If we were to run multiple bonus matches at the same time, I assume Allen would avoid using the same character in more than one match. Which limits us to a maximum of 3 matches running at the same time. My personal picks are Cloud/Mega Man, Crono/Sephiroth, and Mario/Sonic.