Goku coughed up blood after the hard punch Akaza gave him. "Become. A. Demon." said the Upper Rank Three demon. "Like hell I will...!" replied Goku, once again. "Think about it. You could become stronger, and we can fight together for the eternity!" insisted Akaza. "Never!" said Goku, slowly getting up. "Let's make this clear: I do not like you. I'll repeat it one more time: I will not become a demon!" he said, jumping towards Akaza. "Flame Breathing: Third Form -- Blazing Universe!" he exclaimed, slightly slashing through Akaza's chest. "Amazing!" exclaimed Akaza. "Destructive Death: Air Type!" he then shouted, as his long-range punches attacked Goku again. But this time, Goku blocked all of them with his sword, and jumped backwards. Akaza rushed towards him, trying to punch him, but Goku dodged. Meanwhile, Inosuke was watching. (I would like to join, but I can't find an opening... I feel like if I join, I'll just be in the way...) he thought. (And also... I have to trust the boss... He'll surely defeat that demon!) he then tried to calm down. Back with the battle, Akaza tried to punch Goku once again, but the boy cut his arm, which slowly regrew. "Come on, think about it, Goku-kun! Become a demon!" repeated the demon. "I already said no!" exclaimed Goku, trying to cut Akaza. "Fine. That was the last time I asked you. Now I'll just kill you" said Akaza. The demon released a lot of punches to Goku, but the boy managed to block and dodge almost all of them. Unfortunately, one of Akaza's punches slightly hit Goku on the left corner of the forehead, which began to bleed. (Shit... He hit me...) realized Goku. "Flame Breathing: First Form -- Unknowing Fire!" he then exclaimed, trying to severe Akaza's head. But, once again, the demon dodged, though Goku did manage to cut his arms.
"Beautiful!" exclaimed Akaza, regrowing his arms. "Is such a shame I have to kill you!" he said, throwing punches towards Goku. Eventually, one of Akaza's punch hit Goku in the stomach. The boy spat blood. "Ugh..." he grunted. "Second Form -- Rising Scorching Sun!" he then exclaimed, but Akaza dodged. The demon then kept threw punches at Goku, and eventually, the boy got hit on the left eye. (Damn... He hit me in the eye... I won't be able to open it for a while...) thought Goku. "Third Form -- Blazing Universe!" he exclaimed. This time, the attack lands, but barely. "Fifth Form -- Fire Tiger!" he shouted, jumping. A tiger-like figure appeared behind Goku. "Destructive Death: Annihilation Type!" exclaimed Akaza. The two shockwaves met each other, and eventually, they nullified each other. As the dust settled, Akaza had a cut on the chest, while Goku was panting and bleeding. "Did he do that? Did he win?" asked Inosuke. (He's... He's bleeding...) thought Rengoku, as his eyes widened in horror. "Goku-kun! Leave him to me!" he shouted. "No," answered Goku. "There are battles fought to protect life and others fought to protect pride. Right now, I'm dealing with the second type, so don't get in the way." Suddenly, Akaza spoke up. "Oh, what a beautiful phrase, for being someone who's about to die!" he exclaimed, as his cut on the chest quickly. "See? My wound just regenerated. But what about you? A smashed left eye, bleeding and who knows how your internal organs are doing. Sorry about that, Goku-kun, you should have accepted my proposal..." said the demon. (Goku-kun... Don't die...) prayed Rengoku. Meanwhile, Goku, panting, was still holding his katana. (I have no choice...) thought Goku. (It's risky, and Kyojuro and the others will know... But I have to do it, or I'll die... I only hope this doesn't get messy...). And then, a moment of silence. Then, Goku got engulfed in crimson flames, his katana shining. Then, the boy grabbed it with both hands and declared: "I'm tired of hiding: My real name is Goku Tsugikuni! I have demonic cells inside of me, I'm Yoriichi's son and I know how to use Sun Breathing!". In that moment, everyone -- even Akaza -- widened their eyes in disbelief. "So... You didn't accept my proposal... Because you already are a demon, even if only half of you is..." realized Akaza. "AHAH! I knew it! So why don't we ally?" he then laughed. "LIKE HELL!" screamed Goku. "SUN BREATHING: FIRST FORM -- DANCE!" he shouted loudly. Suddenly, Goku rushed forward, his crimson flames still engulfing him, his katana burning with crimson flames. "Destructive Death: Annihilation Type!" screamed Akaza. Then, an explosion. A crimson vortex appeared, engulfing both Goku and Akaza. The demon tried to hit him, but the boy cut his entire arm in half. Then, he headed for the head, but Akaza moved the sword away. So, Goku cut Akaza's chest downwards, then upwards. Then, the vortex exploded, raising dust. "GOKU-KUUUN!" screamed Rengoku. "BOSS!" screamed Inouke. Then, slowly, the dust settled. (I can see him...) thought Rengoku. Then, the Flame Hashira gasped in horror.
The dust settled, revealing the two fighters. Goiku's left arm... Was broken. "I just broke your arm! What a pity, huh? Can't you just regenerate it?" asked Akaza, while his many wounds regenerated. Goku stood in silence, with his right arm in air, holding the sword. Then, Goku had a vision: His father -- Yoriichi -- in front of him. "What are you doing, son?" he asked. "A broken arm? No problem. Remember: You can't regenerate it, but your wounds heal way more faster than any other human. A broken arm is not a problem to you. Now come on, raise your head and keep fighting." Spurred by the vision of his father, Goku, with his remaining energies, slammed his katana right in Akaza's neck. Then, he wrapped both his legs around Akaza's bust. "I WON'T LET YOU ESCAPE!" roared the boy. (Father... I'm honored to be your son, even if I never saw you in real life!) he thought. "Take this, you bastard!" screamed Akaza, trying to punch Goku. But the boy tanked the punch and remained gripped. (He... He tanked it? How can he be so strong, even in these conditions?) wondered the demon. Then, suddenly, Akaza noticed something: The sun was rising. (Damnit... He's immune to sun, but I'm not... I have to get him off me and ran away!) he realized. Then, Goku's sword got deeper in Akaza's neck. "Goku-kun!" exclaimed Rengoku, grabbing his katana. (I have to help him, no matter what!) he thought. "Do something too, boar head boy!" commanded the Flame Hashira. Inosuke immediately rushed forward with both his swords. "Beast Breathing: First Fang -- Pierce!" he exclaimed. "OUT OF MY WAY!" screamed Akaza, punching Goku in the stomach. Goku's legs lost their grip, and the boy flew away, rolling aside. Fortunately, he managed to keep his katana with him. Inosuke and Rengoku got pushed away by the shockwave. (I have to refuge in the forest...) thought Akaza. (I didn't kill Goku, nor the Hashira... And the boy with earrings was not even there... But at least, I discovered that boy's true nature! If he really is the son of the man who terrorizes my Lord, then he's way more dangerous than the earrings boy!) he thought. Then, Akaza heard a voice. "DO NOT RUN AWAY, ASSHOLE!" it was Inosuke. "Just know this: The winner is the boss! He protected me, Mr. Giggle-Eyes and all the passengers! he didn't let anyone die!" he shouted. "YOU'RE THE LOSER, AND THE BOSS IS THE WINNER, YOU HEAR ME, FILTHY ASSHOLE!" he then screamed. (Speak all you want, I'm not running away from you, but from the sun...) thought Akaza. Then, he disappeared. The fight was over, but Goku was in critical conditions. Rengoku slowly walked to him, who was lying on the floor. "Goku-kun... Thanks" he said. "If you had let me fight that guy I would probably be dead, You indirectly saved my life." Goku, barely conscious, smiled. "Eheh... Now you owe me a beer..." he laughed weakly. "Always joking..." muttered Rengoku. "Listen, Kyojuro... Everything I said, was true..." whispered Goku. "I believe you, Goku-kun. Everyone does. Now rest, I'll drag you to the Butterfly Mansion, don't worry" said Rengoku. "Don't worry, boss! We won't let you die!" exclaimed Inosuke. But Goku already fainted.
A few minutes later, Zenitsu arrived. "So... A Upper Rank demon showed up, and he fought him on his own?" he asked. "Precisely, yellow boy" confirmed Rengoku. "He has his left arm broken. His left eye was damaged, but he didn't lose it. We have to bring him to the Butterfly Mansion, he needs immediate cures" explained the Hashira. "I think we should tell his secret to the others" said Inosuke. "We will. This 'secret' is not a secret anymore..." muttered Rengoku. Then, the Hashira carried the fainted Goku on his shoulder, and alongside Inosuke and Zenitsu -- who was carrying Nezuko inside the box -- made their way back home.
Chapter 18 - End.