Decided to jump around just a little bit. This one is tough, definitely, not because there aren't really good cards for each character, because there kind of is...but that doesn't mean they fit perfectly with each other really lol. So part of the choices here won't reflect the very best card for each charcter necessarily, but the best choice for hopefully minimizing crummy procs lol.
|Card 4||Card 2||Card 1||Card 3||Card 5|
|Ability||Significantly weaken DEF of opposing team.||Extremely strengthen ATK of your tactics.||Extremely strengthen ATK of your heroes +CT.||Significantly strengthen ATK of your team.||Extremely strengthen ATK of your bruisers.|
So, this set up is really just about the best you can do. Making sure Star Lord isn't one of his usual speed versions so that IF Gamora procs, at least it will be 3 cards instead of 2. Drax has an ok proc, and Star Lord may be kinda crappy, but at least it would hit everyone.