Along the way they find Phoenix Man’s shredded body. Waganma recognizes the costume from a comedy show called Animal Kingdom, where the character could revive no matter how it was killed. As Child Emperor considers this, Phoenix Man suddenly revives in a stronger new form. Child Emperor confronts him, using five layers of transparent film, but Phoenix Man pierces straight through them with his Beak Attack.
Realizing he cannot stop Phoenix Man on his own, Child Emperor breaks down and is forced to summon his ultimate weapon, Brave Giant. Phoenix Man quickly analyzes the mecha and points out its weakness. Child Emperor is reminded that Brave Giant has an activity limit of 2 minutes and 38 seconds, meaning the fight must be decided within that time.
Phoenix Man verses Child Emperor
Instead of continuing the battle, Phoenix Man shows interest in Child Emperor and his “costume.” He sends him into Phoenix Space, a mental world shared by those who wear costumes. There Phoenix Man explains that he wants to recruit Child Emperor, believing he has the qualities needed to become a powerful costume monster.
He talks about how he could never trust anyone when he worked as a mascot and claims Child Emperor feels the same loneliness. Phoenix Man offers to become someone he can trust and proposes creating a new organization based on spiritual unity. He then grabs Child Emperor’s hand, kneels, and declares that he needs his strength, revealing his plan to monsterize him and guide him into becoming a costume monster.
Child Emperor refuses Phoenix Man’s offer, breaks out of the Phoenix Space, and slams him to the ground. Phoenix Man immediately counters by activating Prominence Hawk Mode, blasting Brave Giant backward and smashing the mech through several pillars. He takes a battle stance and claims that once the child sees his true power, he will eventually come around. Phoenix Man then switches to Phoenix Fire Falcon Mode to boost his speed and unleashes a rapid flurry of attacks. As he circles Brave Giant, he declares that he will peel off its armor like an apple, forcing Child Emperor to keep surpassing his limits and accept monsterization.
Child Emperor uses Brave Giant
Child Emperor fights back by drawing an energy whip and activating 20,000 Fold: Rope Skip Grinder, using it like a jump rope to slam Phoenix Man into a pillar. The two clash in mid-air until Phoenix Man fires his Phoenix Flares, which Brave Giant successfully blocks. Phoenix Man is then caught off guard when he becomes trapped in an electromagnetic web that Child Emperor secretly deployed while flying. Child Emperor takes the opening and lands a punch, but Phoenix Man blocks it and activates Full Power 10000C° Prominence, beginning to melt Brave Giant’s fist.
Realizing there is water beneath them, Child Emperor removes the output limiters and dives downward with Phoenix Man. As they fall, he reflects on Phoenix Man’s words of encouragement, realizing that no one in the Hero Association had ever spoken to him like that before.
The attack unleashes a massive surge of water that sweeps away both Saitama and Child Emperor. As Child Emperor moves to save Saitama, Phoenix Man returns in his new Phoenix Penguin Mode. With control over ice, he uses the Phoenix Antarctic Iceberg Attack, blasting Child Emperor through another level of the base, which turns out to be the burial site of the Subterranean People.
Phoenix Man’s pasts
Believing Saitama to be an innocent bystander, Child Emperor releases Waganma so he can share the barrier with him. Phoenix Man then attacks with an energy blast and, when Child Emperor tries to fight back, declares it useless and drags him into the Phoenix Space. There, Phoenix Man shows the corpses of the Subterranean People as an example of how groups collapse due to a lack of unity, contrasting them with monsters in costumes who share the same will. Through their mental link, he exposes secrets of the Hero Association and reveals what its higher-ups have been doing behind the scenes.
Phoenix Man then explains his own past, revealing he was once a mascot who was fired unfairly and continued wearing the costume until he could no longer remove it, eventually becoming a monster. Child Emperor is shaken and nearly swayed by his words, tempted by the promise of glory as a monster. Just as he begins to falter, Saitama suddenly appears and bluntly states that becoming a monster brings no glory at all.
Phoenix Man reanimate Gale Wind and Hellfire Flame
Zombieman contacts Child Emperor through the communicator and gives him an update. He confirms that the weaknesses Child Emperor predicted for the enemy robots were correct and thanks him on behalf of the heroes. Zombieman tells him he’s glad he’s with them, which moves Child Emperor to tears. He jokingly suggests getting milkshakes after the battle and checks on him. Child Emperor says he’s fine, wishes Zombieman well, and turns back to Phoenix Man.
Phoenix Man then fires beams of light that reanimate the corpses of the Subterranean People, as well as Gale Wind and Hellfire Flame. All of them attack Brave Giant at once. Phoenix Man tries to force Child Emperor to become a monster by slipping a Monster Cell into the cracks of his suit. Child Emperor spits it out and says that being a hero isn’t about wearing a costume, it comes from within. Enraged, Phoenix Man threatens to punish him by slurping out his brain.
Saitama appears
As a final move, Child Emperor activates Gigavolt Smash, releasing a powerful surge of electricity that shocks Gale Wind and Hellfire Flame back to their senses. Brave Giant is destroyed in the process, and Child Emperor is thrown toward Phoenix Man, who tries to finish him off. Saitama suddenly appears and stops the attack. Phoenix Man mocks Child Emperor for abandoning his suit before time ran out, but Child Emperor counters that Phoenix Man relies too much on his own suit. Phoenix Man laughs, saying the child can’t win without Brave Giant and that the previous attack only scratched his eye.
Phoenix Man suddenly breaks into uncontrollable laughter. Child Emperor reveals he planted a Tickle-Tickle Bug between Phoenix Man’s face and beak, explaining that removing it would require taking off the suit, which Phoenix Man refuses to do. Phoenix Man’s body begins to glow before exploding. When the smoke clears, he is revealed to have reverted into Monster Chick Man, a tiny and extremely weak chick-sized monster. Child Emperor wins the battle.
Child Emperor defeats Phoenix Man
Afterward, Saitama praises Child Emperor for his courage and determination, calling him a good hero. Child Emperor thanks him, but then realizes who Saitama is and grows suspicious, wondering if Genos could be a traitor since Saitama was deep inside the enemy base. At that moment, Gale Wind and Hellfire Flame, having regained their senses after the electric shock, attempt to take Child Emperor hostage to lure Flashy Flash. Saitama knocks them both out instantly. Child Emperor looks up their data and learns they are S-class criminals, and is impressed that Saitama defeated them so easily.
Child Emperor offers to escort Saitama and Waganma to the surface. Underdog Man appears, having survived his fight with G5, and the group rides on his back as he leaps upward. They are chased by several of Orochi’s dragons, but Saitama effortlessly destroys them and wonders if they were the cause of the strange noises under his house. Child Emperor asks Waganma if there are any other hostages, but eager to escape, Waganma lies and says there are none. The group continues their escape toward the surface.
