First off, the the Acolytes obviously have no idea of Xavier’s motives in this. They see it as simply another assault against their by Xavier. Besides Anne Marie, they all figure either he wanted Magneto out of the way but didn’t want to break pacifist ruling (which like, it is, but they don’t realize it isn’t just principles, it’s personal, he and the others do not know about the history and relationship between Magneto and Xavier) or perhaps is hoping to use Magneto’s powers for his own cause. Anne Marie sees it as a deliberate perversion thing by Xavier, like he wanted to just corrupt the purest beacon of hope that mutantkind has to rub it in their face.
On an individual to individual level…
Fabian thinks this is great. He can use Magneto as a martyr to rally cause in his name (“LOOK WHAT THEY DID TO HIM! IT IS WORSE THAN DEATH! THEY COULD NOT EVEN GIVE HIM THAT DIGNITY, TO AT LEAST DIE AS HIMSELF!”) and manipulate the incensed crowd with their anger, giving him power to make them do anything he wants, and he never even needs to bump Magneto off like in the comics, which means never putting himself in danger as the murderer, covering it up, etc. He gets to look blameless in this because he actually is, and he still gets all the benefits that murdering Magneto would have gotten him.
Naturally, this means that he doesn’t WANT Magneto’s mind returned (though he claims to, of course), but he doesn’t need to sabotage the efforts that Anne Marie and the others are making. He knows there’s not telepath in Brotherhood (or on Earth, probably) that can undo something XAVIER did. So he can go on and appear to make every effort at helping captive Magneto recover his memories because he actually *is* making every effort, since he knows there’s no chance of it actually working. He doesn’t have to PRETEND to give it his all, he actually does, and thus he can make that much more of a big production out of it for his audience.
An all without getting his own hands dirty.
The hands his followers are now eating out of in their righteous indignation.
Delgado does see what has been done Magneto as being deeply wrong, and he supports the rescue and recovery efforts, but also feels like the first priority still needs to be protection of mutants en masse. He can’t do anything to help with this, he’s not a psychic, so he just sticks to helping those he can instead. He helped with the abduction itself but he stays out of everything else, so Erik rarely sees him except as guard outside his quarters.
Chrome will be enraged. Free will is such a huge deal to Chrome. He might kill a human politician for the policies they enforce, but he would never be ok with mind-controlling them. Which he actually debates a lot with himself over, because he thinks it’s immoral to NOT do it if it’s what needs to be done for good of mutants but he just has such a knee-jerk reaction to it…anyway, he’s going to be disgusted on a very deep level by this. It’s going to galvanize him against Xavier and X-Men much more than if simply had killed him. And he going to drag Xavier so hard for this. Because Chrome’s other Hot Button is hypocrisy and double standards, which he will see this as. He will demand to know, why just Magneto, huh, why just him? Why not Senator Kelly, why not Graydon Creed, why not the Purifiers, why not the Friends of Humanity, why not every skullbashing bigot in the nation? Why do they all get deemed worthy to keep their brains but magneto the one you decide has to be lobotmized into your little lap pet?
He is going to be OUT FOR BLOOD
Anne Marie, oh my god. Just IMAGINE Erik dealing with this person who comes in every day and alternates between religiously reverential and this WEIRD SCARED ANGER LIKE SHE’S SO VISIBLY FREAKED OUT BY HIM BUT ALSO ENRAGED BY HIS EXISTENCE AND SHE’S VIOLENT she doesn’t hit him but she will hit the wall or spontaneously bang her own head on it and she’s doing these psychic barrages to him daily trying to bring him back, talking about how he’s this Savior, this Messiah, how they need him, staring in his face too close with desperate eyes like a thirsty man hallucinating water in the desert, twisting his emotions, forcibly amplifying them to intense degrees trying to bring him back somehow past Charles’s mental blocks, putting him through all these ups and downs as exhausting as any physical torture, all the while screaming about how she’s going to HELP him she’s going to SAVE him just like he’s going to SAVE all of them she has to help them by helping him she has to because he has to get better he has to come back he HAS to and they WILL get through this there WILL be dawn after the darkness—
and then she’s crying because from her POV she’s being asked to basically be the one who saves the Savior, to be responsible for bringing back ALL OF MUTANTKIND because that’s what she equates with Erik, as we’ve been over, this is on her shoulders and if she fails they’re all doomed and it’s so clear she is failing and THIS IS TOO MUCH–
She will TERRIFY him, man
And Fabian, of course, will be there to be the comforting reasonable party who always comes to his rescue when it’s about to be too much.
Just in case Erik ever gets better and remembers all this
And maybe…because he likes to watch >3
