WARNING: The following contains spoilers for Marauders #17 by Gerry Duggan, Matteo Lolli, Edgar Delgado & VC's Cory Petit, on sale now
By any measure, Storm is among the most powerful of the X-Men, a bold leader with the power to back her up. While her control over weather patterns is typically a somewhat flashy power thanks to their scope, Ororo Munroe also can be used in far smaller, more lethal ways.
In Marauders #17, Storm just deployed her newest combat technique, a lightning-powered punch, against Callisto in the Crucible and proved that she now has an Omega-Level one-hit finishing move.
Storm is an Omega-Level Mutant, defined in-universe as mutants whose abilities have "an undefinable upper limit of that power's specific classification." This classification extends to Storm thanks to her god-like control over weather patterns, with her abilities having no defined limit with even other figures in the Marvel Universe failing to match her sheer power. Storm's powers often come in flashy ways, such as her controlling the elemental forces of the world around herself with ease. But they can also be used in smaller functions, such as Storm using her abilities to control air flows to allow her and others to effectively mimic flight.
One of the most deadly applications of Storm's powers just appeared in Marauders, and she wasn't happy about using it. As a ritual on Krakoa, the Crucible has become the way by which depowered mutants take the first step to regaining their powers, fighting to the death so they can then be resurrected by the Five with their powers intact. After months of working with the Marauders, despite having lost her powers, Callisto decides that it's time to go through the Crucible and be reborn. With Apocalypse no longer on Krakoa and therefore not able to run the institution he created, Silver Samurai has taken over and now asks that mutants bring a volunteer to do them the honor of ritualistic combat. Callisto chooses her old rival Storm, who eventually and reluctantly agrees to the fight.
While Callisto is initially expecting a knife-fight -- befitting the pair of them, given their history -- Storm refuses to raise a blade against her. Instead, Storm jukes and dodges around every attack before taking advantage of an opening to lay a single punch against Callisto. Charing the strike with lightning as she does, Storm is able to electrify Callisto's heart with the attack -- instantly killing her. Smoke even comes out of Callisto's mouth as she drops from the blow, with Storm catching her body before she falls. Storm's attack seems to be an instant-kill attack, which is a useful tool for the hero to have, especially with the chaotic events of something like X of Swords still fresh in her mind.
Storm's lightning punch is an exciting new application of her powers, even if it's one that she won't want to use all too often if it can be avoided. Storm's powers theoretically make her one of the most dangerous mutants on Earth, but she can't typically unleash them in battle without risking plenty of other lives in the process. Therefore, it's especially exciting to see her discover an application that can work within confined areas and affects enemies directly with a blow that can bring down any kind of fighter. If another incident similar to X of Swords forces Storm into a duel, she has a one-hit knockout punch.