X-Men had continued to specialize in one-off stories, but much like the Avengers, and the Fantastic Four, they quickly found their major antagonist. Magneto (who appeared in the first issue) and his evil mutants (popping up in #4) became regulars in the early issues of X-Men, much like Dr Doom had a few years earlier in FF, and Zemo and the Masters of Menace in the Avengers.
But there really had been little development of the individual characters. Yeah, Bobby (Iceman) and Warren (Angel) had a little feud going and yes, we knew that Scott and Jean were in love with each other, but the team still really hadn't been fleshed out much beyond that.
X-Men #8 (November 1964), while still a one-off story, offered some interesting developments that would characterize the team for the rest of their history.
The book starts with what by now had become somewhat cliche in X-Men stories; an introduction in the Danger Room, where the drills were being ordered by Scott:
Later that page was the end of the snowman-looking Bobby, as he adopted the chiseled ice sculpture look that would characterize the rest of the series. It was a good move.
We had always heard that the outside world distrusted the mutants. Now we found out just exactly how much. While on a break in Greenwich Village, the Beast saves a little kid who has climbed up on a water tower. But the crowd quickly turns ugly:
This was a theme that would recur over and over in the X-Men, and clearly Stan is drawing parallels to racial prejudice here. Angered over his treatment by the crowd, Hank quits the X-Men and becomes a pro wrestler. Of course, he was the second Marvel character to enter the ring; Spiderman had a brief career as a grappler as well.
The Beast discovers the newest menace facing humanity: a fellow wrestler named Unus the Untouchable. Unus' power lies in his ability to fend off any attack:
Hank observes the Mastermind, one of Magneto's minions, in the audience. Afterwards, we learn that Unus has asked to join up with the Evil Mutants. He comes across a bank robbery in progress and steals the money from the crooks. When the X-Men face him they discover his invulnerability. Returning to the school in Westchester County, they discover that Hank is back.
But is he on the side of good or evil? He is using his scientific knowledge (previously undiscussed) to create a ray that will dramatically increase Unus' powers. At first the X-Men fight to prevent him from using the ray, but he succeeds in bathing the villain in its beam, and it turns out that he was acting for good, as Unus discovers his uncontrollable powers prevents him from doing certain necessary things, like eating:
This idea of a villain so powerful that the only way to defeat him is to make him more powerful is one that would recur many times over the years. The Beast reverses the ray's effects and Unus agrees to go back to the wrestling ring (apparently the authorities don't want him for the bank robbery).
Overall issue comments: A solid story with some movement forward in the characterization of the X-Men, especially the Beast and featuring beautiful sequential art from Jack Kirby. Unus did not go on to become one of the major villains in the Marvel pantheon, but aside from that this is an excellent example of the Marvel magic.