The DD series began to hit its stride in these issues. For starters, each issue featured a new villain. In #3, DD first faced the Owl, who would be a longtime foe. In #4 we first met the Purple Man, an intriguing character who could convince anybody to do anything by force of his personality. Although the villain in DD #5, the Matador, was not terribly interesting, the artwork, which had been handled by Bill Everett in the first issue and Joe Orlando in #2-#4, was turned over to Wally Wood. Although Wood did not last long, his influence on the character is undeniable.
On the romance front, it becomes obvious in these issues that Foggy is pursuing Karen romantically. This adds for an additional dimension to the usual "if only I dared tell her that I love her" that was a staple of the Marvel superheroes of the time. Now Matt has to feel guilty about being in love with his best friend's girlfriend.