The only one that I'm find easy so far is Scrapper Blackheart. I use Omega Sentinel and Cyclops. Omega Sentinel's targeting laser lets you use melee attacks as well as crit people. Cyclops Optic Blast now applies Flanked to the target so the Brawl follow up attack will actually hit .
yeah, the flanked upgrade is nice and I've used it just like you did. I read the report on how to beat em on the Outhousers Avengers Alliance FB page. Good stuff. Thanks to whoever posted that: dholtom?
I just don't have the patience to use Omega Sentinel...even tho I got her up to 11th. I have a great cyclops, too, but he never seems to deal the REAL damage I need.
I usually use Wolverine and some other random character, being careful not to go 'opposite class' of the blackheart.