Cancer Survivor, writing about Health and Fitness as you age

I've said in my book review of the Keys to the Kingdom series by Garth Nix, that the books are complex in my opinion, but I thought that perhaps I have not truly done the books justice. This is me remedying the situation and explaining myself more completely. Background:  The story is about a boy, Arthur, who is given a key by a mysterious stranger who appears to him just as he is about to die. Unbeknownst to Arthur, the situation has been manipulated by the first of seven parts of the will left by the mysterious Architect. The key gives Arthur strength and he becomes the Rightful Heir to the will and the keys. The will was separated into 7 different parts, each held by a trustee together with a key, but they did not honour the Architect's wishes. "The will must be done" Why are these books so complex? Well if that background wasn't enough to make your head spin, I'll try and clarify.  Part of it is my expectation of what the author will do to a charact