Not all heroes play nice. For that matter, not all heroes are nice. Blackheart certainly isn't. Source of terror for criminals and monsters far and wide, she gets the job done no matter how badly she has to traumatize the bad guys unfortunate enough to get in her way while she does it. She goes into the dark places other heroes hesitate to enter, doesn't hesitate to get her hands dirty doing the right thing, and has decades of experience making the worst kinds of walking nightmares wet themselves when they find out she's coming for them. Help her or stay out of her way, she doesn't care which one you choose.
Blackheart is a PL 11 character to add to your Mutants & Masterminds campaign.