The devils in "Young Goodman Brown" and "The Man in the Black Suit" have different appearances and goals. In "Young Goodman Brown", the devil appears as a sinister old man and succeeds in corrupting Goodman Brown's faith. In "The Man in the Black Suit", the devil appears as a charming businessman but fails to change the protagonist's beliefs. While both aim to undermine the protagonists' innocence, only the devil in "Young Goodman Brown" fully achieves his goal of corruption.