Adult themes, graphic violence. I wouldn’t recommend for anyone below their teens.
The series is entirely self-contained and doesn’t take place in any other comic continuity, so it’s very easy to pick up. Save for the last story, it doesn’t even really reference the first volume.
Overall, the series is great. The only complaint I have is that sometimes the artist and story don’t match up as well as I’d hope, but overall it’s a great read. Highly recommended.
I like the first trade collection just a smidgen more than the second, but that’s a personal preference.