I’ve heard Colson works really well with C4rol but I do use stun a lot (Gamora) so does anyone have any thoughts on who would be best to champ. Both of them have an extra cover in my queue and, of course, I can’t champ both, unfortunately. The rest of my roster is here https://mpq.gamependium.com/rosters/jtsings/ just in case someone has a specific third I can use with both of them. C4rol is currently my only 4* champ.
Coulson works best with Carol. His countdowns work well with her passive.
Coulson. Gamora would be the choice if you had 4* R&G ready to go as well. But she doesn’t work all that well with C4rol because they both want all the black they can get.
Coulson is okay with C4rol. You still need 5* Hawkeye to get it to work since she doesn’t fire powers that often (or another characters that fires powers often).
I’m much more of a fan of Wasp/C4rol/Medusa.
You don’t need Hawkeye. All you have to do is fire Coulson’s yellow.
And if Coulson is higher level, Carol’s green will help with that. Cloak and Dagger work great with them, too, fueling either of the key powers.
Thanks for all the insight all, I did champ Coulson tonight and despite my doubts of being able to do so, I may be able to actually champ Gamora as well; thanks to my 2* farm. It looks like she might be the featured 4* coming up in story mode, so that’ll be fun to play with her champed and boosted as well 
Unfortunately, Medusa is one cover away from being champed, need either a yellow, or a red and I only have two covers of wasp, but even my 1 black cover carnage, level 180 Medusa and champed Carol can sometimes wreak havoc on enemy teams, so Medusa is definitely in my sights as a must have champ.
C&D are at 1/1/5 right now so I’ve got a lot of work to get them close to champing, unfortunately, but they do seem to play really well with Carol.
Yeah, that is always an issue at this point. RNG tends to lead to really uneven distribution, so you’ll have some really well covered and others very poorly covered until you’re most of the way into a given tier. And Murphy’s Law means that the ones that work well together are usually split between the two groups.
Just as a follow up I have to say that I’m extremely pleased I was able to champ both because the trio of Carol, Gamora, and Agent Colson can be pretty ruthless and fast too. A lot of times all I have to do is just make enough blue for Gamora and the game starts going downhill quickly for the other team . (And that’s without switching Gamora to 5 red and 3 black because I’m just too lazy lol). Thank you all again for your helpful comments though, I think I needed to be sold a little more on Agent Colson before I champed him but he no longer needs to be sold anymore because he’s a key component to the team.
I think the best team for Carol is Star Lord and Beast. The special tiles get insanely powerful when you have her passive set at 5. Has the added benefit of being a rainbow team with the potential to do massive damage in every color.
Beast? Why not have done with it and chuck Sentry in. Shedloads of countdowns.