1967

The X-Men: 

Cyclops/Scott Summers

Iceman/Bobby Drake

Beast/Hank McCoy

Angel/Warren Worthington III

Marvel Girl/Jean Grey

Professor X/Charles Xavier

Allies:

The Mimic

The Banshee [superhuman hearing, sonic screams, flight, concussive blasts and sonic energy lances]

Dr. Strange

Foes:

“Factor Three”: The Banshee, Ogre [mechanical genius], Mutant Master, The Blob, Changeling [shape shifting, telepathy and levitation], Mastermind, Unus and The Vanisher

Super-Adaptoid [capable of copying the powers and skills, including equipment and clothing]*

The Warlock [psionic abilities to control the mind of others, illusions, psionic force bolts, telekinesis, teleportation, force fields and altering his own appearance as a result of a mutation induced by The Caretakers of Arcturus, plus immortality thanks to the possession of a fragment of the Bloodstone]

Cobalt Man [power armor that grants him flight and repulsion rays like Iron Man]**

Juggernaut

Tyrannus [immortality, psychic powers, genius intellect] ***

Mekano [exoskeleton that increases his strength and speed]

Synopsis:

A terrorist organization named Factor Three appears. Their leader, Mutant Master sends two agents to capture Xavier. Of the two, The Banshee was being controlled by a mental device, so he is freed by the X-men and the other agent; Ogre, is captured. The Mimic leaves the group after some differences with the other X-men. After facing a couple of threats, Professor X who was keeping secretly captive in a locked room in the mansion the menace called Juggernaut, intents to change his mind, failing in the process and freeing him accidentally, occasioning another fight with the X-men and leaving him comatose. With the aid of Dr. Strange, Cyclops and Marvel Girl are sent into the Crimson Cosmos (a world created by Cyttorak to house the prototype gemstone of the actual gem that granted Cain Marko his powers) to find the prototype gem while the rest tried to stop Juggernaut. Back on earth, the X-men use the prototype gem first on Xavier to remove whatever influence had befallen him during the failed experiment, and also on the Juggernaut. When the prototype ruby made physical contact the Juggernaut was pulled into the Crimson Cosmos. Thanks to The Banshee the X-men finds Factor Three’s hideout. It is later revealed this organization plans to cause a nuclear war between USA and the Soviet Union, which would wipe out the human race. The organization splits as soon it´s revealed Mutant Master’s real intentions of destroying both mutants and humans, and that he's an alien with a human disguise. His henchmen turn against him, and help the X-men rescuing Xavier and The Banshee, later he commits suicide to avoid capture.

* Designed by A.I.M (Advanced Idea Mechanics), a terrorist organization, to defeat Captain America. It also fought The Avengers and other characters in the Marvel universe, copying many of their abilities.

** Also fought the Hulk and other Marvel characters. Died in Civil War #1 (2006).

*** Known villain of the Hulk.