Manley Pointer and the Misfit are both morally dubious characters who nevertheless bring about a spiritual re-evaluation in the protagonist of their respective stories.
In "Good Country People," Manley Pointer is a con artist masquerading as a Bible salesman. Unaware of his true identity, the protagonist Hulga initially looks down on him, as she does all the other country people, and seeks to seduce him as a way of validating her nihilism. However, Manley gets the last laugh, tricking Hulga into giving him her prosthetic leg and revealing that he is a true nihilist while her nihilism isn't genuine at all. Her own nihilism is revealed to be the illusion she accused traditional Christianity of being, a way of lashing out at the unfairness of existence. He leaves her stranded in a hay loft, without her leg and without her previous illusions of superiority. The reader is left to decide if Hulga will become a better person as a result of her encounter with Manley.
The Misfit is a bit more complicated as a character, though his effect on the Grandmother is not ambiguous. In "A Good Man is Hard to Find," the Misfit reveals he is a tormented man, racked with spiritual doubt, resigned to the idea that the only pleasure in life comes from "meanness." His despair and agitation move the heart of the Grandmother, a character who has been shallow up to this point. Seeing him in pain, the Grandmother proclaims, "Why you're one of my babies. You're one of my own children!" The Misfit has prompted a moment of grace for a spiritually dead woman, which is why he tells his cohorts, "She would of been a good woman... if it had been somebody there to shoot her every minute of her life."