Man, devil, or both?
Roger Prynne was born in England. Not much is known about him, but the main aspect of his life is that he was married to Hester, but their relationship was not a love story. He sent Hester to New England, but couldn't immediately follow behind her because of some business he had to finish. When Hester got to the New World, her husband's delay was lengthy, many thought he had died, and she committed adultery. He arrived two years after, in the midst of Hester's punishment, and finds out what happened. He vows to seek revenge on Reverend Dimmesdale, who he speculates was the culprit, which changes him to a devil-like human.
Roger's Conflict is probably one of the main strings inside the web of conflicts of "The Scarlet Letter". His hate towards Dimmesdale and his desire to hear the acceptance of the reverend's sin through his mouth is what drives Roger to become the evil human he is portrayed as in the novel and change his relationship with every character there after.
Chillingworth VS The Lovers
External: Conflict external because he took action upon his hate and delved into the reverend's mind. In addition, he followed the three main characters everywhere and harassed them in some sort of way.
"He now dug into the poor clergyman’s heart, like a miner searching for gold; or, rather, like a sexton delving into a grave, possibly in quest of a jewel that had been buried on the dead man’s bosom [...]" -Ch. 10
"[...] might Roger Chillingworth have passed with them for the arch-fiend, standing there, with a smile and scowl, to claim his own. So vivid was the expression, or so intense the minister’s perception of it, that it seemed still to remain painted on the darkness, after the meteor had vanished, with an effect as if the street and all things else were at once annihilated." -Ch. 12
Internal: Chillingworth's hate has consumed him from within, and to such a high degree that Hester can no longer recognize him. He becomes a devilish creature half-way between a demon and a man.
"In a word, old Roger Chillingworth was a striking evidence of man’s faculty of transforming himself into a Devil, if he will only, for a reasonable space of time, undertake a Devil’s office. This unhappy person had effected such a transformation by devoting himself, for seven years, to the constant analysis of a heart full of torture, and deriving his enjoyment thence, and adding fuel to those fiery tortures which he analyzed and gloated over." -Ch 14
"So Roger Chillingworth - a deformed old figure, with a face that haunted men's memories longer than they liked - took leave of Hester." -Ch. 15
Roger Chillingworth is as important of a character as Hester, Pearl, or Dimmesdale. His changing of personality caused the story to have a full turn, it drove the already tortured Dimmesdale insane to the point where he HAD to confess; it gave Hester a chance to look upon herself and see how much she has been able to cope with her pain in comparison to him, but it also provides another side, an emotionally cold and unloving side in the story that shows how much Dimmesdale and Hester love each other, and how little Hester and Chillingworth did.