Warning: contains spoilers for Cable #11!
While Magneto and Professor X may be working in the shadows to influence the future of mutantkind, their partnership just got a perfect new name courtesy of the X-Men's most essential mutant team. Jonathan Hickman's tenure as Marvel's Head of X has seen a new era dawn for the entire line of X-Men comics, with Charles Xavier founding the nation of Krakoa, gathering all of Marvel's mutants together and beginning the process of resurrecting all those who have died in the years he's been quietly working on this staggering project.
Those resurrections are handled by the Five - five young mutants whose powers synergize to clone mutant bodies, with Professor X using his advanced Cerebro helmet to implant 'back-ups' of each mutant's memories and personalities, effectively bringing them back to life. In Cable #11 - from Gerry Duggan and Phil Noto - the Five are asked to illegally resurrect the original Nathan Summers to help take down the evil clone Stryfe. They consent to do so, knowing that Krakoa's Quiet Council - composed of twelve of Krakoa's most influential mutants, including Xavier and Magneto - won't punish them with so many mutants still to resurrect.
It's in the process of negotiations that the Five's mocking term for Magneto and Professor X is revealed, when mutant healer Elixir asks if they're really being asked to "risk one of the helmet bros' fury." Unfortunately for him, Xavier enters a few moments later, pointedly replying that, "the 'helmet bros' have been brought up to speed." The 'bro' label tends to be a favorite of Tony Stark - with Stark and Bruce Banner going by "science bros" and Doctor Strange reluctantly admitting he and Stark are "awesome facial hair bros" - but here it's a fitting term for the headwear-sporting masterminds of mutantkind, both because of their new costumes in this era and the insidious meaning behind Professor X's recent transformation.
Magneto's helmet is an iconic part of the character, but one that has taken on metaphorical significance over the years. While it creates a menacing aesthetic, Magneto's helmet has also long served to protect him from Xavier's telepathic influence - a literal guard against anyone changing the mutant zealot's mind. Professor X's Cerebro helmet is new to Hickman's tenure on Marvel's X-comics, and allows him to scan and store telepathic back-ups of every mutant on Krakoa. But the helmet both stops Xavier's allies looking him in the eye and metaphorically obscures his vision at a time when he's abandoned his pacifist dream and become fixated on the far future, blind to the moral ramifications of his actions or other possible paths.
Eyes are a favorite visual motif for Hickman, whose series East of West - with collaborator Nick Dragotta - included the supernatural exchange and sacrifice of eyes as a process of gaining forbidden knowledge, with his X-Men revamp telling a similarly sprawling story of the corrupt and ambitious. Intertwined series House of X and Powers of X revealed that Magneto and Professor X long ago made contact with Moira MacTaggert, whose powers have allowed her to live through repeated iterations of the current timeline. She sought Xavier out early in his career, hoping to find an ally who could prevent the coming future, in which AI life would effectively supplant mutantkind as humanity's successor race.
Ever since this was revealed, Xavier has become a cold, ruthless mastermind - even sanctioning genocide - with only he, Magneto, and Moira knowing the true purpose of Krakoa. While 'helmet bros' may be meant in jest, little do the Five know that they just gave a name to a secretive cabal even more influential than the Quiet Council itself, and the perfect one at that. Funny as the name is, the helmet bros are a blinkered, insular team focused on protecting but not bettering mutantkind. The X-Men's most essential team may not know it, but their nickname is the perfect encapsulation of Magneto and Professor X's villainous new path.