3* Deadpool. Either a solid AoE, or a nice cheap hit on anyone above about 6K health.
2* Storm. 50/50 chance, but her blue is awesome.
Ares: I’ve got a couple of teams I use a lot (e.g. Medusa/Blad3/C4rol) that end up with a ton of green, but don’t have a use for it. Onslaught Teamups can be awesome there.
2* or 3* Cap red or blue: In addition to what was previously mentioned, as long as they’re at 5 covers, you can overwrite any tile with the countdown, which can be incredibly handy when there’s an enemy Special Tile off in the corner or something.
GSBW: Her purple is just amazing, never gonna say no to that. Her green is expensive without her self-acceleration, but great AoE and board shake.
Yelena. I know, I know. But still, Payback Mission has saved my bacon a few times against hard-to-get Special Tiles. I often end up with a couple of those after DA-heavy PvEs, and I never toss them.
2* or 3* Captain Marvel red. Niche, but excellent for Nodes with Bullseye and a couple of higher priority targets, or Brute Mindless ones or something. 3* pops all Protect Tiles at 5 covers, which is awesome against someone like Falcon or CMags (like in the final node of Thick as Thieves).
Moonstone’s black. You really want it at 5 Covers, and the ones you get from PvE are always at 3, unfortunately, but this can absolutely destroy teams that are relying on buffing just a couple of special tiles.
2* or 3* Thor yellow. Great green battery and board shake.
Either of 3* Iron Fist’s. Purple is probably the better because it’s more versatile, but his green can be great too, especially if you’ve got someone around with an expensive black, so you’re likely to have the 12 around at some point for the double tiles.
1* Hawkeye: He’s basically useless as an actual character because he’s so squishy, but both his powers are actually pretty good at 5 Covers.
Blad3 black or Torch green. Semi-niche, but the repeating countdowns are great with C4rol when you don’t have room on the team to actually take a character like that.