This one is simple – all characters, no boosts.
No points for matches lasting less than 12 rounds.
In addition to normal points, +1 point for each turn taken in a match.
Teams with Daken/Hulk/Patch/X-Force would be attack magnets for keeping a game around.
Using Sentry on offense would be a bad idea.
spidey/bullseye/falcon teams galore… no thanks 
What about bonus points for using each different power on your team. Obviously if you lose you get nothing but you get increasing amounts of bonus points for using 7-12 unique powers during the match (12 only possible with team-ups). Passive only need to trigger once to count but they can still count.
This would be complicated >.<
Good lord what would this mechanic do to regular PVPs. I only see one point nodes but if I can win a match and use at least 9 powers I can still get reasonable points out of it, yay. Oh wait that took 15 min and I got eviscerated. Boo.
It would be hard for this team to win a match. And it’s easy to beat.
Okay, someone proposed a Colossus/Falcon/whoever (GSBW? Hood? Spidey? lol) team where you use Bird Strike, then use Fastball Special and throw Falcon. AND USE BIRD STRIKE AGAIN. 
How about that? Since Colossus can actually punch people!