Garou erupted from the ground nearby, now with a completely monstrous appearance, and confronted both Fubuki and Bomb. The elder martial artist loudly called for his brother, informing Bang and the other heroes of Garou's new presence. Hearing this, Bang wanted to leave and assist his brother, but he was currently holding off the Black Sperm clones. Having heard all the information as well, and knowing that he probably wanted to leave, Atomic Samurai told him to go and assist his brother, much to the elder's gratitude.
Over on the other side of the battlefield, Bomb prepared to fight the almost completely monsterized Garou, while telling Fubuki to stay back. With insane rage, Garou started engaging in combat with Bomb, and the two of them were capable of holding their own relatively well against each other. Fubuki watched their battle and tried to assist the old man against the hero hunter.
However, they were fighting so fast that her eyes simply could not follow their attacks. As Fubuki appeared to lose her focus, Garou tried to attack her, but Bomb managed to block the strike, then purposefully landed a blow on Garou that sent him flying away, in an attempt to keep Fubuki away from the fight, before immediately rushing towards him.
All across the battlefield, the S-class heroes were locked in battle with the strongest members of the Monster Association.
Eventually, Garou and Bomb continued battling. The older martial artist contemplated Garou's extremely rapid growth, noting that the hero hunter's newly customized style had fused every technique he had ever learned together. Thinking on what to do, he questioned whether it had come about due to monsterification, or something beforehand.
Bomb resolved not to go down until his brother arrived, and he prepared a powerful cutting move. Having concealed the preparation for his attack, Bomb struck the ground, managing to disorientate Garou. Seeing this, he then seized the opportunity to launch an attack, but was shocked to find that Garou perfectly matched and cancelled out the blow. Then, in retaliation, Garou threw a single hit, which knocked Bomb to the ground.
Sadly, Bang arrived just in time to see his elder brother being defeated. Noticing his arrival, Bomb called out to his brother, warning him about Garou's extreme growth, but Bang remained strong, with a stern look in the direction of his traitorous former disciple. Standing there, Bang commented on Garou's miserable state before deciding to go all out against his former disciple, and pretty much his grandson.
In a flash, they began engaging in combat, the two of them extremely capable of fighting against each other. Yet even still, with the pure intensity of the fight, Garou managed to make his former master bleed after a brief clash, causing Bang to remark that he was now much more worthy of teaching than before.
Away from the two of them, King and Metal Bat came back together and entered the battlefield. After King ended up making his grand entrance, stalling both of the cadres, the sensei and student showdown resumed, with Garou taking the stance of the Exploding Heart Release Fist — a fighting style that Bang had primarily used before developing Water Stream Rock Smashing Fist.
Both Bang and Bomb were surprised to see this, with Bomb asking his brother how Garou knew of his style, as Bang had sealed it away a long time ago. It was then explained through the old man that Garou had once broken into the safe that contained the scrolls of secret techniques at his dojo, and had got a grasp of that specific style.
Even still, despite Garou using his Exploding Heart Release Fist, it reminded Bang of his own past self and made him even more determined not to lose.
It was revealed that during Bang's past, he used to be a complete ruffian, who would recklessly challenge any strong opponent and would often put them in hospital. Being disgusted by his brother's brutality, Bomb decided to confront Bang himself and put an end to his rampage. Before they fought, Bomb noted that while his brother thought he had gained tremendous power, he hadn't really overcome himself, and stated that he would have to teach Bang a lesson about properly overcoming oneself. Their fight then began, and shortly after, Bomb defeated his younger brother.
As Bang attempted to spite his older brother, Bomb just told him to chill out for a bit before leaving the area. This loss would come to humble Bang over time and make him see the true error of his ways. Through this, he chose to create a new, defensively oriented fighting style, and decided to follow his brother's footsteps by creating his own dojo.
During the years, Bomb would keep an eye on his brother, revisiting his dojo and smiling with pride at his brother's changed life.
Back in the present, after recalling his memories about Bang and seeing that his brother was being overwhelmed by Garou, Bomb noted that if Bang used Exploding Heart Release Fist, then perhaps he could still stand a chance.