First solution that I have posted, please let me know how I do.
I go this achievement by having Wolverine on my team and Ryu on the other. I did not have to create a Marvel vs. Capcom team, that would also be harder to do online with random people.
Whenever you play a match (if its without a friend) just pick either Wolverine or Ryu and hope the other team picks the opposite and the achievement should pop after the match. Must be online.