How does someones influence change a person?-Pln #3

In my independent reading book Rangers Apprentice #7: Erak's Ransom by John Flanagan, the main characters (Halt) apprentice, Will, is influenced so much by Halt that he is literally a new person. The first 6 books in this series explain Will's struggle to learn all of the rangers ways, and he is also learning how to act emotionally and mentally from Halt, along with the physical needs. When ever Will has to make a big decision, he asks himself "What would Halt do?" every time. I think that the authors point is show how much he is changing. Not only is Will changed by Halt, but Halt is changed by Will. At the beginning of the story Halt is a gruff man who never smiled, but as Will comes into his life, he learns that he is growing attached to Will. When Will is awarded for saving the city, Halt smiles for the first time. When Will is asked whether he wants to stay a ranger or be the Princess's body guard (his dream as a child) and he chooses ranger, Halt cries for the first time. So as you can see, Halt is transformed from one man to another by Will's influence, just the same as how Will is transformed.