What is the transformation of chillingworth's self image and identity that he holds primarily responsible for that transformation?

Some townspeople have an innate intuition and are skeptical of the physician's true motives. They sense that Chillingworth has undergone a profound change since arriving in Boston, going from a genial old man to an ugly and evil person. Thus, "it grew to be a widely diffused opinion that the Reverend Arthur Dimmesdale ... was haunted either by Satan himself, or Satan's emissary, in the guise of old Roger Chillingworth.” Chillingworth is being consumed by his own revenge and evil control issues. He is essentially a "leach" drawing the life out of Dimmesdale. Chillingworth holds Dimmesdale responsible for this.