Whether or not they're members of the X-Men, mutants come in all shapes, sizes, hues and most importantly, power levels. Matthew Malloy is a mutant who might just have been the most powerful of all. For a long time, the highest power level a mutant could attain was classified as Omega Level. These were mutants like Jean Grey or Iceman, who were believed to have powers that could theoretically cause apocalyptic scenarios or world-altering events.
Matthew's existence was revealed during the aftermath of Marvel's Original Sin crossover in Brian Michale Bendis and Kris Anka's Uncanny X-Men #23, and he proved to be just as powerful as any Omega Level mutant, and maybe even exceeded them in terms of raw power. While the precise level of Malloy's strength was never fully revealed, Xavier certainly thought of him as a special case, as he decided to intervene in quite an invasive manner. Now, CBR is re-examining his story to see whether or not he could reasonably be called Marvel's most powerful mutant.
MATTHEW MALLOY'S ORIGIN
Like many powerful mutants, Matthew's powers manifested earlier than his more regular mutant counterparts. He was discovered by Xavier quite early in his assemblage of X-Men hopefuls, and registered as the largest power signature on Cerebro ever. After witnessing several events around Matthew involving psionic energy decimating the surrounding area, Charles decided to initiate contact via a child-like projection of himself, to remain safe and better relate to the young mutant.
Seeing that Matthew's powers over reality were adversely affected by extreme emotion, Xavier manipulated the relationship he built with Malloy to covertly install mental blocks in the young man, slowly dampening his power. Eventually, Matthew grew so powerful that he saw through Xavier's deception, confronting him. Luckily, Matthew saw reason in keeping his powers in check, opting to have his memory wiped entirely so he could pursue a normal life.
HOW MATTHEW MALLOY'S POWER WAS UNLEASHED
While that arrangement worked well for a while, the mental blocks that Xavier placed in Matthew's mind began to deteriorate after his death. What's worse, the X-Men wouldn't find out about this looming threat until the Original Sin storyline, where Xavier's previously hidden last will and testament came to light. The will detailed his experience with Matthew and called upon some of his X-Men to ensure his work to keep Matthew and those around him safe continued.
Prior to the X-Men's arrival, Malloy had accidentally destroyed a small town in an emotional episode and then disintegrated a S.H.I.E.L.D. response team, organized by Maria Hill, who arrived shortly after to investigate. When Hill tried to bring in superhuman telepaths (Exodus and Headlok) to assist with communicating with Malloy, he detected the intrusion and used his psychic abilities to seemingly kill them from miles away.
HOW STRONG IS MATTHEW MALLOY?
Matthew's mind began unfurling as memories and confusion flooded into the powerful mutant. While the X-Men tried to reason with Malloy, Maria Hill decided that Matthew was too dangerous and ordered a full Helicarrier bombardment that decimated everyone present, including the X-Men.
Following the bombardment that killed Cyclops, Magik and other X-Men present, Matthew simply resurrected himself. Despite being just a skeleton, he reformed in a grizzly manner and destroyed the Helicarrier with little effort. Meanwhile, Beast observed the energy readings through Cerebro, stating that these occurrences showed power beyond anything he'd seen, "beyond Omega Level." Matthew goes to the X-Mansion for help but is attacked by those who though that he was mroe directly responsible for the death of the other X-Men. In the ensuing conflict, he proceeds to wipe out more of the X-Men.
HOW MATTHEW MALLOY WAS DEFEATED
While the situation was going south, a young mutant named Tempus traveled back in time, using her temporal abilities. She opted to arrive in the past at a time that predated Xavier's discovery of Malloy, a time where the mutant hadn't even been born yet. After explaining what would come of him eventually, Xavier opted to make sure Matthew wasn't born by dissuading his parents from ever initiating contact.
While a little extreme, this wouldn't be the first or the last time Xavier was morally dubious to enact his perception of the greater good. With Matthew removed from existence, the incidents of the story were reversed, with no one having recollection of it apart from Xavier and Tempus.
IS MATTHEW MALLOY THE STRONGEST MUTANT?
Although Matthew is no more, we can still get an idea of how powerful he is stacked against other powerful mutants from his feats. Between self-resurrection, reality manipulation, psionic and telepathic prowess, his power set is astronomical. It's safe to assume he'd be able to dispatch Omega Level mutants like Iceman, X-Man and Gabriel Shepherd without much difficulty. Although these mutants are powerful, Shepherd even being a proto-mutant, their powers are beholden to the universe they exist within. With Malloy's power over reality, he can manipulate the laws of the universe that govern these powers.
Reality-warping mutants like Legion or Mr. M are the only other characters who could reasonably pose a threat to Malloy. In terms of raw, indefinable cosmos-shaking mutant powers, Franklin Richards, the son of Mr. Fantastic and the Invisible Woman, is probably the most capable of taking Matthew on in battle. As an incredibly powerful mutant with seemingly limitless power and potential, Franklin has done amazing things, even making Galactus his herald in a far flung future. Given that Franklin is considerably smarter and has a better grasp on super-powers than Matthew, who's list of achievements pales in comparison to what Franklin has demonstrated the ability to do.
While Matthew is certainly one of the most powerful mutants in the world. he probably isn't the most powerful mutant, given the limited amount of information we have about his powers. Since he's been called a "beyond Omega Level" mutant, it's not even clear if he would technically "count" as an Omega Level mutant or if he would would fall into an even stronger category.