WARNING: The following contains spoilers for X-Men #11 by Jonathan Hickman, Leinil Francis Yu, Sunny Gho, and VC's Clayton Cowles, on sale now
The unity that the mutants of the Marvel Universe have experienced since coming together in House of X has allowed many of them to realize their true potential. Some have even begun to utilize their powers in new and unexpected ways, working with other power sets to create massive results that can turn the tide of entire battles.
By synching his powers up with Magma and Iceman, Magneto just deployed a new combo attack that easily destroys an entire army of the Cotati warriors spawned from the pages of Empyre.
When the Cotati reach Krakoa, they unleash their forces on the assembled mutants. There are casualties across the battlefield, and the secondary battle happening against the Cotati on the surface of the Moon catch the full attention of many of the other X-Men. But the battle takes a decisive turn towards the mutants when Magneto takes to the field. Using scraps of metal that are strewn across the island, Magneto single-handily decimates the Cotati forces. Calling out to his fellow mutants, Magneto reveals that he approached Magma about the idea of locating any dormant volcanic locations across the island. Magma had discovered them, and her powers over molten rock allow her to force the volcanos to erupt - and to control their output enough that it's manageable and won't damage the other islands around Krakoa.
Using the Cuckoos essentially as a communications device, Magneto has the psychics call upon Iceman. With over twenty tons of magma now spewing out around Krakoa, Magneto needs Iceman to use his powers to counteract the heat - solidifying the molten magma into sturdy and splintered iron. The Master of Magnetism then uses his own near-limitless powers to unleash a torrent of the newly formed spikes. They decimate the Cotati forces before him, slaughtering most of their army. Even when the Cotati general survives the initial barrage, he's brought down by a series of satellites that Magneto pulls from orbit and drops on his head.
The sheer scale of Magneto's attack is to be commended, allowing him to wipe out an entire enemy offensive with just the help of two fellow mutants. It speaks to the power of the mutants on Krakoa and just how effective they've become since truly becoming united around the ideal of the new island nation. It also might suggest the beginning of a very dark path for the X-Men to consider taking. This display of power could be seen as genuine proof that combining the potential of multiple Omega-level mutants into one form could be very impressive, as Bishop has previously suggested.
Now that the X-Men have access to both Sinister's deep-well of genetic modifications as well as the resurrection powers of the Five, they could easily decide to follow Bishop's advice of creating a new multi-powered mutant. While having one person who could do what Magneto, Iceman, and Magma just did would be very useful for mutant kind, it could help lead to a future like one of the timelines seen by Moira X in Powers of X, where Sinister's eventual betrayal and exploitation of that concept ended up dooming the mutant population. While Magneto's massive attack may have helped protect Krakoa today, it may also end up dooming the nation tomorrow.