Well... Here's the main reason I made this match:
Prologue:
On a small island south of Wakayama, used by the military as an experimental site, a mysterious rift in space opened and disappeared, leaving behind a mysterious object, something resembling a totem, a body made of black sand with terrifying faces etched into it. In the center, at the heart of the totem, was a strange machine, and above what appeared to be the totem's arms was a black skull on each arm. On the ground lay a skull and a small note written in a mysterious language.
The military, driven by the mysterious readings displayed by their instruments, quickly arrived at the location. They found the mysterious square totem and acquired it for study. They attempted to decipher the mysterious language, but failed. The only thing deciphered was the correct shape of the totem, where the third skull would be placed, and a name… WITHER STORM.
The mysterious totem was carefully studied, being disassembled. The totem's material was completely unknown to humankind, and the mysterious cube-shaped machine in its chest was… indestructible in every sense of the word, immune to any and all conventional weaponry. The tests continued for a long time… Until one day the world trembled, and then trembled again, and continued trembling, and when it finally stopped trembling… Something shook the foundations of the world.
An alien invasion in Tokyo had only annihilated the city, but as it turned the entire city hall into rubble, a tunnel opened that crossed the planet to Brazil, and a heat explosion almost destroyed the entire planet. With that, the research was temporarily forgotten in favor of studying what remained of the alien invasion. The world had changed forever… and so the totem research was temporarily forgotten.
But time passed, and with the slow and gradual recovery from the damage caused by the alien attack, the study of FTL engines bore fruit, and soon a new space race began, as well as investment in weapons that could prevent another invasion of such scale. With the help of the surviving aliens, the understanding of FTL speed accelerated exponentially, but Japan was unable to keep the technology to itself, and the military's interest suddenly returned to that strange totem and the machine whose hardness surpassed even the metal of that alien ship.
It was after some time that someone had the idea to try to recreate the totem based on the figure in the paper, to try to advance the research, with a black sand as a base, the machine on top, right in the center of the chest, two of the sands back to the right and left of the machine, a skull at each end and finally… The skull in the middle… That's how the military base and the island disappeared from the map, as did the person who had the idea to assemble the totem.
The storm had awakened, and it was ravenous…
The creature flew over the ocean toward the coast of Wakayama. War jets fired guided missiles, helicopters fired machine guns, destroyers fired explosive ammunition that would tear metal ships like the Titanic apart like papier-mâché. Tons of ammunition were used on the ravenous black mass. War jets were caught mid-air by the purple light and devoured, helicopters were blown up by black skulls, and destroyers were lifted from the water by the creature's tentacles, torn apart and absorbed into the black mass.
The military spent an entire day trying to shoot down and prevent the creature from reaching the coast, in order to recover the machine at its core, but they only informed the authorities in the coastal region eight hours in advance. The evacuation of the city's population began, and dozens of heroes went to their posts to fight the creature.
As the creature headed towards the coast, Ryukyu smiled while watching Nejire Chan chatting animatedly with Lemillion and Sun Eater;
While the creature devoured the army, now formed a year earlier, Class A heavily supported Uravity, as the creature was about to embark in the Kansai region. Ochako's parents had moved to a relatively nearby city, with names like Dynamight, Earphone Jack, Chargebolt, Pinky, Creati, Shoto, Tokoyami, Froppy, Invisible Girl, Red Riot, Anima, Tailman, Sugarman, Cellophane, Nighthide, Tentacole, and Ingenium there to help, including the hero who defeated the alien invasion, Deku, who was silently considered the central piece in stopping the creature's attack.
More experienced heroes like Best Jeanist, Gang Orca, Gale Force, Kamui Woods, Mirko, and Mount Lady were organizing in preparation for the attack, all while black tentacles split warships in two..
In a slightly more isolated place, Hawks chatted happily with Endeavor, while his assistants watched them, as Burnin stared at the clock, measuring the time until the creature's arrival, while soldiers floated in the air, swaying desperately as they slowly drifted toward the creature's mouth..
The newly formed Class B team also had several members gathered, including Phantom Thief, Battle Fist, Rule, Comicman, Lizardy, Vine, and Real Steel, preparing for the arrival, while marine life fled as far away from the chaos as possible, their instincts warned of the threat looming above the ocean..
It wasn't long before the storm was visible on the horizon, and by then everyone's role in the battle was already decided.