The Supervillain and Me by Danielle Banas
In Abby Hamilton's world, superheroes do more than just stop crime and save cats from trees - they also drink milk straight from the carton and hog the television remote. Abby's older brother moonlights as the famous Red Comet, but without powers of her own, following in his footsteps has never crossed her mind. That is, until the city's newest vigilante comes bursting into her life. After saving Abby from an attempted mugging, Morriston's fledgling super villain Iron Phantom convinces her that he's not as evil as everyone says, and that their city is under a vicious new threat. As Abby follows him deeper into their city's darkest secrets, she comes to learn that heroes can't always be trusted, and sometimes it's the good guys who wear black.