So, I was getting ready to write a big long review, trying to decide what to say, but I'll leave you to read someone else's review that's pretty much spot on.
I tend to shy away from Card, for multiple reasons, but Stefan Rudnicki, who I love, read/produced this book, and I picked it up cheap. But I will swear that even the readers sounded bored with this book.
Danny, the main character, is just balls out unlikeable. He started out sympathetic, and that crashes. The story behind the gods (beings from another world who have super powers here on earth) has been done. Card does his usual "telling, not showing" routine, and the "special boy comes into his special power" has been done by Card plenty of times before (and better). The sexual content is absurd (it's not offensive, it's just terrible), and after seeing this in multiple Card books, I'm convinced that what he really needs is a good therapist.
What I will give Card is that the magic system in these MitherMage novels is good and interesting. People have a natural affinity for affecting certain things (usually natural - like stone, water, fire, animals, etc.) and it tends to run in families. Along with this specificity, there are strength rankings within those kinds of magic. I like it, unfortunately, unless someone else is writing the same kind of magic system, I won't be reading about it again.