Your roster looks a bit weird with that Steve Rogers oddball, leveled up to 70, while your 2* are still way from finished. Looking at it now, I find it difficult to guess, who your A-team is. Who do you field regularly? Anyway, I think your main mission for now would be to get as many 2* covers as you can, so that you can start a transition to a 2* team. As for “killer combos” go, there are some popular team compositions that you may attempt to use once you get your characters decently powered up. OBW goes well with Astonishing Wolvie (and anyone in particular who can create strike tiles efficiently), as her black ability damage at level 5 gets pumped up by strike tiles. She’s a very useful character to have on her own, too, so try to build her up if you have the opportunity. Classic Storm can fire her Windstorm repeatedly when she’s paired with MN Magneto with a high level purple skill giving her lots of blue - it’s a fun team to play, a bit weak on defense though. Thor combos with Modern Storm, allowing for multiple Lightning Strikes, providing you tons of AP to use. Add OBW to the mix, and choose a desert environment to fight, and you may create an endless loop, where the opponent can do nothing but sit and watch. All of those combinations are reliable and worth using only if your heroes are properly leveled, which means you’ll need some time (or some cash) to upgrade your heroes.