A new era launched with X-Men 20, as comics legend Roy Thomas took control of the writing, Jay Gavin on art chores, followed by Werner Roth and Don Heck.
Thomas was genuinely one of the top writers of the time and is rightly considered to be a legend today. But he did not quite hit the mark to start with on the X-Men. Perhaps there was something about the title, about the premise that made it hard to pin down, it was certainly different to the other comics out there, so maybe it took him a while to find his stride.
The early issues seemed to be trying to pull away from the Lee earlier issues, although the first issue brought a return of Lucifer. Even then though, it just seemed to be filling in unneeded blanks from Xavier's past, and introducing a bigger bad guy behind Lucifer, and apparently killed him off. A number of other villains are introduced, missing some of the flair of the earlier foes, Count Nefaria and his Ani-Men, The Locust, El Tigre who became Kukulcan. Along side these came guest appearances from othe villains of the Marvel Universe, The Puppet Master and Super Adaptroid (copied the powers of the Avengers) with more villains to boot, The Colbat Man, The Warlock (Merlin) and the return of The Juggernaut - again with unneeded flashbacks.
However - there were hints of Thomas really finding his feet, hints of a larger organisation, Factor Three working against the X-Men, they free the Juggernaut in the first place but the most important thing was the introduction of an apparent Factor Three operative The Banshee!
After a run in with the Mole Man and Tyrannus, Thomas began to hit his stride, starting his first major multi part story, as the X-Men went up against Factor Three. With the leader of the team revealed to be The Mutant Master, with operatives Banshee and Ogre perhaps for the first time the X-Men began to show glimmers of it's potential.
Although the main stories were not really above average, Thomas had a knack for the personal, playing up the X-Men's relationships, briging surprising developments along the way, Jean leaving the team to go to college, Calvin Ranking (the Mimic) being there, Cyclops accidently wounding Angel and sidelining - but Angel blaming him for it; Mimic rejoining the team, then losing his powers, Professor X building something to help him walk, then losing it again, Quicksilver and the Scarlet Witch being offered the chance to join the team, but deciding to remain Avengers, a lot of good stuff.
The final showdown with Factor Three pulls out all the stops, Xavier has been kidnapped, the X-Men are on their own, backs to the wall, they win, with the help of Banshee, working for Factor Three under duress they manage to save the day, rescue Xavier and return home.
But there is a twist.
Xavier feels that the X-Men have performed stupendously, that they are not really students any more, that they are a team in their own right. The time for simple matching uniforms is a thing of the past, and the team are given individual costumes, and the X-Men take another small step forward.
This brings the issue count up to 39, and as of 38 the lead story drops in size to allow for a backup strip - the X-Men origins. I'll mention these in the next segment..