Warning: The following contains spoilers for King in Black #4, by Donny Cates, Ryan Stegman, JP Mayer, Frank Martin and VC's Clayton Cowles, on sale now.
Namor the Sub-Mariner possesses plenty of deadly moves in his arsenal. As King of Atlantis and one of the world's most powerful mutants, Namor is truly a force to be reckoned with.
In King in Black #4, by Donny Cates and Ryan Stegman, Namor is among several of Earth's heroes to break free from Knull's grip. Marvel's most powerful heroes release themselves and attack Knull's forces, herding them into the center of New York. And as part of their counterattack, Namor unleashed his most devastating attack against Knull by calling a tidal wave down on the Knull-invested New York.
On command, Namor slams down his trident and unleashes a massive tidal wave on the symbiote-infested city. Incapacitating the symbiotes, this move leaves room for Storm and Thor to electrocute Knull's symbiote hive and weaken the symbiote god. With Knull softened up, Jean Grey is able to probe his mind for the secret to defeating him.
Namor's tidal wave did a world of good for Marvel's heroes, but this move hasn't always been performed in such a heroic fashion. The first memorable instance where Namor unleashed his tidal wave was in 1941's Human Torch Comics #5, by Carl Burgos, Henry P. Chapman, Jack D'Arcy, Bill Everett, George Kaplan, Mike Roy and Henry Sahle. In this issue, Namor went on a crusade against humankind by flooding several cities across the planet. The Sub-Mariner unleashed tidal waves on cities from Berlin to New York.
This catastrophic attack was later emphasized as a foundational moment in the Marvel Universe in 1994's Marvels #1 by Kurt Busiek and Alex Ross. From the perspective of reporter Phil Sheldon, New Yorkers were seen fleeing to shelters and attempting to reach higher ground. Namor's attack left a strong impact on these citizens, as the sheer force of the Sub-Mariner's tidal waves left them overwhelmed. No one could forget how Namor, one of the heroes of World War II, leveled their city.
Years later, in Avengers vs. X-Men #8, by Brian Michael Bendis, Jason Aaron, Ed Brubaker, Jonathan Hickman, Matt Fraction and Adam Kubert, Namor unleashed his powerful tidal waves once more. At this point, the Avengers were hiding from the Phoenix Five in Wakanda. Possessed by the Phoenix Force, Namor demolished The Black Panther's kingdom. The atrocity and devastation that Namor's attack left behind formed a hatred between Namor and King T'Challa.
Both of these previous examples illustrate how vengeful and malevolent Namor's tidal waves can be. Usually, The Sub-Mariner would use this attack in cases of rage against humankind. Between humans who he felt had wronged Atlantis and the Avengers, who were trying to stop the Phoenix Five, Namor has used his power to strike back at those he hated.
This time, however, Namor seems to be using his power on the side of good. Rather than attacking humanity, the Sub-Mariner is saving New York's citizens from Knull. While Namor has flooded New York before, this time he does so to save the city rather than destroy it. Instead of fighting heroes like the Avengers, Namor is now working alongside them to save the Earth, once again.
With the fate of the entire planet is at stake, Namor has to put aside his petty differences with humankind to save his kingdom. Despite the desperation of his circumstances, it's quite the twist to see Namor using one of his most powerful attacks for a more noble, heroic cause. Namor's tidal waves may have an angry, vengeful history, but they ultimately serve a noble purpose in King in Black.