Khan’s story
It just seemed like that after the type of lifestyle Khan lived, being abused and beaten, he had two directions he could have taken. Either he would have been an aggressive and hostile dog that nobody wanted or he could rise above his past and head to a better and brighter future.
The character of this dog was so strong that he naturally was able to overcome the emotional trauma from his past and be a better dog for his new family that loved and appreciated him. It is just amazing to us to think that an animal could be so aware of its surroundings and mindset.