We cannot wholly condem one form of media. That's like asking if there are bad TV shows. We all know there are, but are we going to never watch it? I believe everything comes down to balance. How much time do you spend watching TV, or listening to music, playing a video game, or reading (comic) books? Match that up against how much time you spend in prayer, or reading your Bible, or at church. If you spend to much time in the fantasy that comics offer, your perceptions begin to change. Do you believe you can fly? No. But the values begin to change, and ever-so-slightly you become immune to things that would have triggered an emotion in you. You become callous, and accept some things as normal.
This is the area that we must be careful with in our children. As parents, we must stay a part of their lives and monitor what they are doing. Be that balance for them, so they stay grounded to the reality that there is a super power-and that is GOD! Do not rip the book from their hands, but show an interest in what they do-whether it's comics or video games, do not leave them on their own in their rooms for hours. Whatever you do, be a part of them, and do it with love. If you keep them close, you'll know if they are reading 'bad' books, or playing 'bad' video games.
I wanted to post because, I have about 10,000 comics in my collection, and I thoroughly enjoy them, but nothing compares to God's grace.