I'm calling shenanigans on the line of bull about "we're the only thing between humanity and unspeakable horror". The last panel basically makes it clear -- yeah, it's a dirty job, but when you start abusing your power because it's more convenient than doing a little legwork, and then on someone who annoys you or just because you feel like it -- that's when you start becoming part of the unspeakable horror.
What I'm getting at is that the chief difference between 'good' empowereds and 'evil' ones is how they use their abilities. So when the good guys start acting like being in the line of fire gives them the excuse to do whatever they want -- well, that's when they stop being good guys and start being bad guys with a different team jersey.