1968

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:

Red Raven [flight using mechanical wings]*

Foes:

Frankenstein (a robot replica of The Frankenstein Monster)

Jack O´Diamonds [radiation resistance, diamond body, telepathy and teleportation gained from exposure to radiation]

Grotesk [superhuman strength, durability, agility, impenetrable force field, infrared vision, resistant to telepathic attacks, adaptability to extreme environmental conditions, mechanical genius, all gained from exposure to radiation]

“The Brotherhood of Evil Mutants”: Magneto, Quicksilver, Scarlet Witch and Toad

The Avengers {Hawkeye, Black Panther, Goliath and Wasp}

Juggernaut

The Maha Yogi (previously known as The Warlock)

Quasimodo (Quasi Motivational Destruct Organism, a droid capable of human-like emotions)**

Computo (sentient super computer intelligence in charge of a hive-like structure full of robots created by Quasimodo)

Mesmero [hypnotism]

Polaris [magnetism manipulation]

Battling Grotesk, the only survivor of an underground civilization called “Lava Men”, Professor X orders the X-Men to stay put in the HQ while he confronts the menace himself, failing in the process and dying on the same explosion that killed their terrible foe. In his last moments, he confesses he was dying already from and incurable disease, so he decided to sacrifice himself to protect the X-Men one last time. Later, they discover a message left by Xavier, in which he reveals he was secretly training Marvel Girl for her to have a more powerful telepathy, preparing them for Magneto’s return. Quicksilver, who was a recent member of The Avengers, accepts a proposal from Magneto to rejoin his group of evil mutants in exchange of a cure for Scarlet Witch, who apparently has a rare disease now, but neither of them entirely trusts him. Out of confusion, The X-Men battle The Avengers, who have come to check on Quicksilver and find him unconscious on the ground after fighting Cyclops. Magneto’s plans fail again and both The Avengers and the X-Men manage to escape. Toad helps Quicksilver and Scarlet Witch to escape the island before it exploded, leaving Magneto behind due to his constant bullying behaviour towards him. Magneto´s goal of mutant superiority over humans is reaffirmed by the mutant Mesmero, who uses a horde of droids to fight the X-Men and mankind in the name of Magneto himself, abducting Lorna Dane (Polaris), his daughter, and using this link between them to manipulate her against their enemies with the aid of a droid that looks like Magneto. Cyclops uses a disguise and the fake identity of a mutant named Erik The Red to infiltrate Mesmero’s facilities and rescue Lorna, who discovers she is being manipulated and helps bringing down Mesmero’s plans.

* Guardian of a lost race of bird men that Angel found on a secret island. 

** Created by Mad Thinker, a known villain of the Fantastic 4.