I can imagine a Denarian whose MO was just giving people power and then letting them go out into the world.
At first, they use the power to do good. Then, as time passes, they do a little something selfish here, a little something selfish there. They hurt someone by accident a couple of times, then they start to do it a little on purpose, then it slowly becomes the default.
Years pass, and what's left is a bitter, cynical host that is just perfect for that particular Fallen.
A Ghost Rider type character (well, one of the incarnations thereof) could make a good model for such a person. They've crossed the line into where hurting people is acceptable, but not quite to the point where it doesn't matter any more.