To unwind a bit last night, I played a game of Marvel Champions, using Klaw as the villain against my Iron Man/Leadership deck, and my new Black Widow/Justice deck (pre-built expansion). Both of the heroes are ones that seem to intend for you build up in Alter-ego form, then flip to Hero mode to start busting heads, though I still went ahead and changed them to Hero mode to clear off the starting side scheme.
Things went pretty well, with me slowly building up damage on Klaw, keeping the threat down and eliminating minions quickly. I felt like I was having some trouble getting into a rhythm with BW, having her in Alter-ego form when I needed to be in Hero to use her Preparation cards, but managed a couple of pretty nifty combos here and there.
Both of my heroes took heavy damage, but got Klaw’s first stage down to 2 HP, and then I lucked into a double Supersonic Punch draw for IM. Between his Tech cards, the two punches, his Allies, and his basic Thwart, I was able to finish off the last 2 HP, activating Klaw’s second stage and bringing out the Immortal Klaw side scheme (adding 10 to his health), then hammer him for a bunch of damage, bringing him down to 10 HP and leaving just 2 Threat on the Immortal Kang side scheme. BW was easily able to take out the last 2 Threat, eliminating Klaw’s bonus 10 HP and winning the game.
I thought the two heroes synergized well, working together to take out minions and ping Klaw here and there. I know that my end finale was primarily luck of the draw, as you probably aren’t supposed to take out the villain’s second stage in a single turn, but it definitely felt heroic! 
EDIT: The more I think about it, I think I forgot to add the extra 18 HP to Klaw for using two heroes. That would explain the ease of the last turn. So, flawed victory! I likely would have triumphed on the next turn, but it is possible I could have lost, as both heroes were down to 5 HP. The world will never know…