Normally, the helmet is used to keep telepaths out of your head. Would the helmet work in reverse: when a telepath wears it, their abilities can't affect anyone?
I tried searching for the answer to this, and the only relevant thing I found was an old thread on Reddit, but no actual answer.
In New X-men #137 Kid Omega uses a copy of Magneto's helmet to suppress Professor X's abilities
.
Yes. Magneto's helmet can indeed work in reverse, rendering a telepath like Charles Xavier unable to utilize their abilities while wearing it.
The X-Men '97 animated series (Season 1, Episode 9: "Tolerance Is Extinction - Part 2") provides a clear example of this very scenario. During the episode, Magneto forcefully placed his helmet on Xavier's head, effectively blocking Xavier from using his telepathic abilities.
Initially, Wolverine managed to remove Magneto's helmet, allowing Professor X to use his telepathic abilities and get inside Magneto's head in an attempt to undo Magneto's most recent villainous act.
However, things took a turn when Cyclops had to intervene and stop Xavier (you'll have to watch the episode for more juicy details, true believers!). This brief window gave Magneto the opportunity to put his helmet on Xavier's head, completely shutting down the Professor's powers.
The MCU film Deadpool & Wolverine (2024) also explores this concept with Cassandra Nova, Xavier’s twin, who possesses similar powers. In the movie, Cassandra and other characters operate under the assumption that placing Magneto’s helmet on Cassandra’s head would neutralize her abilities. Deadpool even suggests this idea to the other heroes. However, it was revealed that Cassandra had already melted Magneto’s helmet… after killing him, forcing the characters to seek an alternative solution.
In the comic book "Unbeatable Squirrel Girl Beats Up the Marvel Universe!" set in the canonical Earth-616 universe, the superheroes (including Iron Man) believe that a telepath wearing Magneto’s helmet would have their powers blocked.
When Squirrel Girl's clone, Allene, goes on a rampage (hence the "beats up the Marvel Universe" part), it takes a massive team effort of superheroes (and some supervillains) led by Squirrel Girl herself to stop her. After subduing Allene, the team locks her up in an Iron Man-operated prison cell… with Magneto's helmet firmly on her head. Apparently, they all think she controls squirrels telepathically (she doesn't).
Allene isn't too thrilled about sporting the helmet, though. She complains about the itchiness and even worries about incurring Magneto's wrath for borrowing his signature headgear:
Allene (to Squirrel Girl) : Dude, I'm locked in a cage with no squirrels to keep me company. Plus, plus, the squirrels I duplicated are all kept in a different cage off-site. Could you please tell them we don't control squirrels telepathically??
This hat itches like crazy. No wonder Magneto's so testy all the time.
Plus I'm pretty sure if Magneto finds out I'm biting his style on the regular, he's gonna be even more irritable than he normally is, which is to say: quite a bit??
During Astonishing X-Men Vol. 3 #44-47, a weird non-bald Prof. X (who is referred to as "Savior") from another dimension, captured 616's Cyclops. Savior wanted Cyclops to be used as energy for some creepy engines so that they could prevent their world from being destroyed, but Cyclops would have to die too...
Sounds terrible, huh? So Cyclops started a violent revolution with other prisoners: a Wolverine, a teen Nightcrawler, and a Mrs. Summers-Emma. Finally, the teen Nightcrawler puts Magneto's helmet on evil-long-haired Xavier’s head... Well, that's how the evil Xavier failed...
Absolutely, it would work the same on 616/Prime Earth, I think.
