Bang, and then Bomb, and then Bang and Bomb start whaling on an already diminished Garo, and Genos is reasonably confident the old dudes have this in the bag. But he underestimates Garo’s almost bottomless stores of resentment and disdain for the heroes of the world.
As a kid, he was always made out to be the monster while so-called “heroes” beat him up, just because he was weak and unpopular. The monster never got to won. This fuels a fourth or fifth wind for Garo, but the battle is interrupted when he is airlifted out by a big talking bird monster.
I have to say, I’m as pissed off as Garo, Bang, and Genos about this twist. This was supposed to be the Hero Hunter’s final battle; this episode should have brought some kind of closure to his story (and this season), even if it ended with him meeting Saitama’s fist. But that expected period became an ellipsis. Clearly OPM has other plans for our bloody-eyed friend.
As Garo exits the stage prematurely, Centichoro appears in all his very big, evil-looking CGI glory. As skilled as Bang and Bomb are, their gifts just aren’t that effective against an enemy so freakin’ huge, while Genos is similarly hamstrung by a firepower limit that can barely scratch Cent’s carapace. Even Bang and Bomb’s final one-time combo attack only works temporarily; the centipede simply shrugs it off molts.
Genos offers to stay behind, but the old-timers don’t think that’s right. Young’ins need to live on; Genos’ own scientist mentor said as much. But Genos ignores the advice of his elders, because he doesn’t think it’s right to let the old protect him while he sits back and watches.
So he blasts off and starts going at Centichoro, pushing him away from the civilian centers, blasting through one of his teeth, entering his digestive tract, and incinerating him from the inside out. As he’s spat out of the boss’s mouth, all his clothes burned off, it looks like his reckless abandon did the trick…but it just wasn’t enough.
That’s when Bang, Bomb, and Genos finally run into a little luck, as “S-Class” King starts egging on Centichoro with a megaphone, telling him he’s brought his rival, “Blast”. Of course, he’s only serving as bait for Saitama, who arrives just in time to save King from being squashed like a bug.
Saitama steps between King and Centichoro, rushing at him at full speed, and delivers his One Punch special, totally eradicating the monster, just as we all knew he would. It doesn’t matter how much other heroes struggle in vain to defeat a boss; Saitama will always make it happen.
That’s why it seems like a bit of a letdown he wasn’t able to deliver a punch to Orochi, chopping off the head of Monsters, Inc. so the body will die (or alternatively, punching all of the monsters into oblivion, Orochi included). Instead, Genos is yet again inspired by his master’s excellence, and Garo is probably off to be transformed into an actual monster. Those twelve episodes just flew by!