Possibly one of the greatest defensive cards in Champions.
Just outright prevents any and all damage. There are precisely 6 heroes at this time (July 2022) that have a card or cards that can prevent all damage, but none of them also stun the attacker. (Backflip: Spider-Man, Bad Boy: Star-Lord, Shield Block: Captain America, Mockingbird: Hawkeye, Cartoon Physics: Spider-Ham, Mass Increase: Vision)
Six out of 33 makes it clear just how powerful this card is. But itdoes require a an additional cost: Vision being in Mass form. And there's only one, whereas Cap and the two Spiders each have two copies of theirs.
Ultimately Backflip may come out on top, but that means we're debating whether Mass Increase is better than the defensive card that is still -after several years- the best defensive card in the game. That is some rarified atmosphere. I just wish I had any reason to play Vision.