In a Nutshell
Magneto attempts to counsel the now-villainous Scarlet Witch.
Writer: John Byrne, Roy & Dann Thomas (Issue #60)
Penciler: John Byrne, Paul Ryan (Issue #60)
Inker: Paul Ryan, Danny Bulanadi (Issue #60)
Letterer: Bill Oakley
Colorist: Bob Sharen
Editor: Howard Mackie
Editor-in-Chief: Tom DeFalco
Issue #56: Scarlet Witch, having embraced her power and darker urges in the wake of her recent losses, torments the Avengers she's captured. Meanwhile, at Avengers Compound, Hank Pym is visited by Quicksilver, and Iron Man receives the Avengers emergency signal. Investigating Scarlet Witch's cottage, Pym watches as Magneto arrives, then bursts through the wall. Magneto insists he's only there for his daughter, but Pym draws a weapon from his pocket and turns it on Scarlet Witch. Just then, Quicksilver rushes in, knocking out Pym and declaring his allegiance lies with his father and sister. Issue #57: Human Torch arrives and attacks the mutants, prompting Magneto to fly them away. They're attacked in the air by Iron Man but Scarlet Witch disables his armor, sending him plummeting to the ground. The three mutants arrive at the newly-rebuilt Asteroid M, and shortly thereafter, he Avengers proceed to infiltrate the base.
Magneto and Scarlet Witch make short work of them, however, and Magneto sends the Avengers back to Earth in the wreckage of their Quinjet, over the objections of Scarlet Witch. Issue #60: On Asteroid M, Magneto tests Quicksilver's loyalties, exposing him as a double agent. Scarlet Witch savagely attacks her brother, but he retrieves a shrunk-down Lockjaw and teleports the three of them to where the Avengers are waiting. They attack, but Scarlet Witch suddenly falls into a trance. Magneto tries to flee with his daughter, but is unable to penetrate the strange force field that has enveloped her. Sensing this isn't the work of the Avengers, he flees until he can learn how to overcome the force affecting his daughter. The Avengers pursue him, with Iron Man knocking Magneto into a smokestack, which promptly explodes. Iron Man emerges from the blast, but Magneto is nowhere to be found. Later, the Avengers investigate Scarlet Witch's condition, just as the time lord Immortus appears before them and declares she has been elevated from pawn to queen.
Firsts and Other Notables
These three issues constitute Magneto's involvement in the "Dark Scarlet Witch" storyline, a storyline that John Byrne had been building towards since he took over Avengers West Coast, putting Scarlet Witch through the emotional ringer by destroying her family, leaving her slipping in and out of a catatonic state (as seen in various chapters of "Acts of Vengeance") and attracting the attention of Magneto, concerned for his daughter's well-being. This culminated in Scarlet Witch emerging from her catatonic state for good in a deranged state, determined to kill the Avengers.
At this point in her history, Scarlet Witch's hex power enables her re-alter reality (so instead of causing bad luck to happen to her target, reality is altered such that the outcome preferable to her occurs), something which will play a large role in the X-universe in the mid 00s, when she uses her powers to create the House of M reality and then wipe out the vast majority of (non-commercially viable) mutants on M-Day.
Avengers West Coast #57 unveils a new Asteroid M, rebuilt following the destruction of the last one (by Warlock, in New Mutants #21). Magneto notes its intended as a secondary base of operations, in addition to the Hellfire Club (where he is still, technically, the Gray King of the Inner Circle). This is the version of the base which will appear in X-Men (vol. 2) #1-3.
Lockjaw is an dog-like Inhuman (one of the genetically-modified beings who live on the Blue Area of Earth's moon) with teleportation abilities (it goes back and forth as to whether he's a dog with teleportation abilities, or an Inhuman mutated into a dog), while Immortus is the oldest iteration of the time traveling villain Kang, who resides over Limbo (but not Illyana's Limbo) and concerns himself with the well-being of the timeline. Iron Man at this time is pretending to not be Tony Stark inside the armor, claiming to be a different person hired by Stark to serve as Iron Man, for reasons. Most of the Avengers, particularly the ones who know Tony well (like Hawkeye & Wasp) aren't buying it, but continue to humor him. Avengers West Coast #56 contains a second story depicting the reunion between Captain America and the original Human Torch (who is a member of the West Coast Avengers at this time), as well as a one page editorial comic from John Byrne apologizing for the continuity gaffe that led to Tigra appearing in "Atlantis Attacks" despite events in Avengers West Coast which should have prevented that.
Issue #57 marks the end of John Byrne's run on Avengers West Coast (which began with issue #42). Byrne has said he left the book (and Avengers) in protest, after Tom DeFalco told him he couldn't do the Dark Scarlet Witch/Immortus story he was already deep in the middle of when DeFalco told him to stop. The odd thing, though, is that, near as I can tell, the way the story wraps up isn't vastly different from what Byrne had planned anyway (in that it involves Immortus; his larger plans were more sweeping than what got published, of course).
Issues #58 & 59 are mostly unrelated fill-in issues, featuring alternate timelines being culled by Immortus (something he'd been seen doing in previous issues as well), then in issue #60, Marvel vet Roy Thomas and his wife Dann(ette) take over the series (and stay on the book nearly through to its end, leaving just before the final issue, #102), bringing the Immortus elements of the story to the forefront and ending Magneto's involvement in the Dark Scarlet Witch story, which then concludes in issue #62.
Scarlet Witch, with the Avengers trapped unmoving in some kind of stasis field, appears to torment Wonder Man (who is in love with her) with what is implied to be some kind of...evil, mystical...hand job (there goes my Google hits counter!) or castration (though his crotchal area appears undamaged in later panels). Apparently, as Byrne originally drew it, the implication of what she was doing to Wonder Man was even worse.
A Work in Progress
Magneto declares that one should only take a life only if absolutely necessary.
He also insists his concern has always been for the preservation of mutantkind.
It's noted that Iron Man's armor is not magnetic, something which Magneto wryly notes prevents him from trying to save the Avenger after Scarlet Witch knocks out his system.
US Agent, perhaps serving as John Byrne's mouthpiece, equates Magneto to Hitler.
In nice bit of attention to detail, Byrne makes a point of establishing that the Avengers have personal force fields, enabling them to travel through outer space without wearing a full space suit, and similarly provides Human Torch with a means to use his powers in the vacuum of space.
Issue #57 ends with the Avengers at Magneto's mercy, yet he simply deposits them safely back on Earth, saying his days of slaying defenseless foes are behind him.
The cover to issue #56 is an homage to Uncanny X-Men #243.
While these issues (and the subsequent ones which wrap up the storyline) are significant to the development of Scarlet Witch's character and the role that plasy in future developments in Avengers, for the moment, they are chiefly of interest to X-Men readers for their depiction of Magneto. Other than "Acts of Vengeance", this is the only other notable appearance of the character between the Claremont-penned Uncanny X-Men #253 and #269 (he does make two other appearances; they are not as significant), a time when the character is considered to have reverted to outright villainy following his time as the leader of Xavier's school.
However, even in these issues, written (mostly) by John Byrne, the man credited with spearheading the "return Magneto to villainy" effort, Magneto's portrayal is not as simply villainous as in his pre-Claremont days. His chief motivation is the well-being of his daughter, and while he makes little effort to change her new, more villainous attitude, it could be argued he simply recognized that trying to do so would just make her worse. Furthermore, he does make every effort not to kill anyone (or allow anyone to be killed) throughout this story, even heroes he's sparred with before, even though in several cases it would be easy to do so.
Bottom line, it doesn't take much work to reconcile this Magneto with the Magneto to whom Professor X entrusted his school, the Magneto who, hardened by the events of "Mutant Massacre", agreed to an alliance with the Hellfire Club at the insistence of Storm and who was pushed back into a darker state of mind by by the death of one of the students in his care. Toss in Claremont's attempt to smooth over these more overtly villainous appearances (from X-Men #253), that Magneto is simply playacting the role of the villain to give anti-mutant sentiment a clear target, and it's even easier to reconcile the two Magneto's. He reads very much like a villain acting the part in these issues, one in full villainous regalia flying people to and from his orbital asteroid base, but also someone motivated chiefly by concern for his deeply suffering daughter, who is very careful not to kill anyone and, indeed, prevents his daughter from harming anyone significantly once he's on the scene. This Magneto and Claremont's Magneto are not, in fact, as different as they may appear.
Tomorrow, a "Cross-Time" fill-in in Excalibur #20, followed by more drug-fueled fun in Wolverine #22 on Friday. Next week, Uncanny X-Men #260.