Tony is an artistic/right brain individual that has always believed in the notion of something out there that can't be explained. When his sister's legs become paralyzed without any explanation, he gets the idea from her acupuncture treatment that voodoo may be the cause. By making dolls for people he has never met, he provides them with a weapon to get back at someone that they feel deserves a pin to the stomach, leg, or any other body part.
With each new client, Tony hopes to see someone fall under the same result as his sister, and only then will he fully believe that voodoo caused this to happen to her. He believes with great conviction, that only then can he can seek out those responsible, and reverse it.