Heart of the Ninja: Water — T.J. Perkins

Duncan has survived his greatest battle - but the fight is far from over. Now paired up with a new instructor, he is being drilled in the ways of a master adept to control the presiding power growing inside him. But time is running out, the enemy is preparing to strike, and Duncan is far from ready to be the great protector he's meant to be. Uncertainty grows and with it comes a new threat - mysterious assassin cells welding a Dark Ninja Magic that binds the users with a demon. To save everyone on his team Duncan's inner power takes over, but the loss is more than he can cope with. Alone and rejected by his friends, mistrusted by his own people, Duncan must now master his power and set things right before the Dark Ninja Magic consumes them all.