I remember reading a book that was about a boy learning to control his shadow, everyone had their own shadow and his was particularly weak. I recall early on he had to fight someone much stronger with a dragon shadow, but that's about it. Anyone know what this book is called? I've been looking for years, and all my attempts have turned up empty. I believe he may have been attending some sort of school, I think the fight with the dragon shadow was some sort of coming of age test. If I remember anything else I'll place it here.
The boy with two shadows, by Margaret Mahy. http://www.penguin.co.nz/products/9780143504405/boy-two-shadows
A witch wants to go on holiday, so persuades a boy to look after her shadow, which sticks to his feet alongside his own. But the boy's shadow is bullied by the witch's shadow, and runs away.