Great book for most kids
I read this whole series from about ages 8-10, and I loved all of it. I barely flinched at the violence at the time, but looking back on it there were some cynical message and lots of gory death and violence. I found the Gloamgloazer story arch delightfully dark and loved the world building and rich characters.
The world of the edge is ever increasingly expansive and exciting and is one of the best developed worlds I've ever read. Kids will love the diverse characters. Although most of the story lines center on male protagonists, the creatures are diverse, and don't all fall victim to the trope of dim and brutal giants. The story does well by not having a good vs evil conflict, few characters are purely good are evil and there is moral conflict-without it being too much for my eight year old mind of the time to understand. There are plenty of strong female characters with really interesting story lines, and most children will see themselves represented in one character or another.
I think this book series is great, if a little gory, but you shouldn't underestimate a child's ability to process new information and ideas. Some more squeamish kids might hesitate at some of the darker and more gruesome elements, but I loved it and so will most children aged 8+