I loved Avatar the Last Airbender, so I naturally gravitated towards this book. The book has very similar elements--no pun intended--to Avatar the Last Airbender. You have a child protagonist, joined by other child protagonists, who all have mystical abilities. They go on a treacherous journey to find an ancient relic, and there are enemies along the way.
This is a great book for an elementary school student to get into. It's a pretty easy read, not a lot of complicated phrases or vocabulary. It's also a great book to read if you're an artist-type, or one who appreciates art.