What if Tanjiro was a Pure Saiyan? (DB X KNY)

Godlike Speed & Tanjiro's Mark

Tanjiro let out a scream of the ages that could rival even his ape form.

Daki from atop the roof yelled, "Onii-chan!" Tanjiro widened his eyes as he saw himself in Gyutaro's position. He thought to himself, "At every turn, one false step, and I could've found myself in that same situation. I was lucky enough to remain a human, but there could've been a future in which we were both demons. But even if I end up turning into a demon, I'm sure... that someone in the Demon Slayer Corps will do the favour of beheading me."

The situation in front of the boy got intense as the demon began to push himself up. Gyutaro groaned as he reached for the kunai in his leg. Tanjiro kept up with his scream while Gyutaro finally held the kunai. Tanjiro thought, "Cut through! Cut through! Win! Win, no matter what! We're going to win!" Tanjiro's blade pierced his neck as tiny drops of blood came out.

-With Daki-
Daki watched the situation from afar as she said, "Hey! Are you kidding me? Don't get beheaded by someone like him!" She sent her belts to Tanjiro to help out her brother. But before they could reach him... the rubble on top of Zenitsu began to spark with electricity. Zenitsu was freed from the rubble and cut every belt that was going for Tanjiro. Daki looked at him in confusion and said, "Damn him! He pulled himself out of the rubble! Out of my way, ugly freak!" Daki then redirected her attacks to Zenitsu. Zenitsu dashed around in the air dodging the belts. Zenitsu mentally uses,

"Thunder Breathing... First Form..."

Daki spoke as she sent another wave, "I know how fast your move is! I've seen it so many times!" Zenitsu uses her belts as a springboard and finishes,

"Thunderclap and Flash... Godlike Speed!"

He gripped his blade and launched at Daki at a speed even faster than any Hashira could manage. A bolt of lightning was produced by Zenitsu as Daki thought, "So fast!" Her neck was taking the form of cloth as it began to rip from Zenitsu's attack. Daki thought in fear, "M-My head's being severed! Damn! I didn't think he could move like this!" Zenitsu thought with absolute determination, "Cut through! Cut through! Follow through! I can only use Thunderclap and Flash Godlike Speed twice! It saps the strength from my legs! I've already used it once to escape the rubble, so this is my last chance! And I won't get another chance to go for her neck if I don't do it now! Tanjiro created this one-in-a-million chance! I'm going to slash her for sure! For sure!"

-With Tanjiro's battle-
Gyutaro began to groan louder as he slowly raised himself higher. Tanjiro thought, "Dammit, I can't cut through! It's too hard! The poison should've weakened him! Am I still not strong enough?" Gyutaro successfully pulled the kunai out and let out a yell. Blood slashes were let out as Tanjiro thought, "He's already recovered from the poison! I'm being engulfed! I'll get slashed! My sword's being repelled!" Gyutaro finally pushed Tanjiro back as he thought, "I was so close! I was close to..." Gyutaro still sent slashes at him as he blocked them and continued, "Don't give up! Don't give up! Don't give up! Hang on until the end!" Gyutaro yells, "You little punk!" He then started to throw scythe attacks at him as he kept his defence up. Tanjiro again thought, "His attack speed... is increasing! He's breaking down the poison! He's making a full recovery! Don't give up! Don't give up!" Gyutaro let out an ear-deafening scream and was about to slash Tanjiro. In just the nick of time, Tengen saved Tanjiro with just one hand. He blocked the scythe and went for a slash that exploded and sent Gyutaro back. Gyutaro thought, "He's not dead! He wasn't dead! His heart... I get it! He used his muscles to force his heart to stop, huh? That enabled him to temporarily stop the poison from circulation!"
Tanjiro yelled, "Uzui-san!" Tengen yells, "I've finished my Musical Score Technique! We're going for the win!" Tengen dashed at Gyutaro as Gyutaro responds with, "Don't make me laugh!" Gyutaro sent another attack as Tengen rendered the attack and played it like an attack. While charging, Tengen redirected and blocked the attacks as he said, "Ichi! San! Shichi! Go! I! Kin! I can read it! That filthy score of yours!" Tengen then blocked every single attack while charging at Gyutaro. Gyutaro thought, "He deflected all of my Rotating Circular Slashes!"
Tengen appeared from the smoke and tried to slash Gyutaro who dodged. He landed on the side of the building and angrily thought, "'Score'? Did he say 'Score'? Did he turn my Blood Demon Art into a song and deflect it? When he only has one arm? No way this is possible! Don't give me this crap!" Gyutaro pushes himself toward Tengen as they made a clash that demolished most of the area. Both of them blocked and ran around while attacking each other. Gyutaro kicked him down and threw more slashes at Tengen, who responds by blocking and redirecting the attacks. Tengen then explosively dashed at Gyutaro and pushed him back. They went through most of the buildings and kept up with the attacks. There was a short pause because Tengen coughed a bit of blood. They then stood in one place and threw many attacks that were heard in the night sky. Both screamed as explosions erupted around their battlefield with constant blood slashes and firework-like attacks. The battle kept getting faster and more fierce. Most buildings, well... buildings that weren't destroyed before were destroyed by the sheer force of their attacks. They both fought on and left behind trails of explosions that liquified some shingles. Tanjiro finally joined the fight after thinking how Tengen is still alive and fighting even better than ever with one hand. Tanjiro thought, "Amazing! He's holding his own! But that's not enough to defeat him! Uzui-san's going to reach his limit first! I have to do it before that happens! I have to cut off his neck!" Tanjiro skids to a stop and dashes at the fight head-on. Both kept on with the fight while Tengen slowly started to lose the upper hand. Gyutaro cut the chains from Tengen's cleavers and snapped them. He then delivers a scythe to the right side of his abdomen but Tengen cuts his right arm off, earning himself a slash on the left side of his forehead to his cheek. Tanjiro let out, "Uzui-san!" Tengen stabs Gyutaro in the stomach and orders, "Don't stop! Jump!" Tanjiro jumped into the air and dropped down as Gyutaro thought, "You're too slow! You little dumbass!" Tanjiro had the scythe go from under his chin and through his tongue. Gyutaro thought, "Even if you have someone pave the way for you, a loser is still a loser! It's all over now! The poison will surely kill you this time!" Tanjiro thought with anger, "I'm gonna slash you! I'm gonna behead you! I'm not giving up! I'm so going to behead you!" Tanjiro raises his sword into the air and brings it down onto Gyutaro's neck making contact. Gyutaro thought, "Damn you! Still swinging your sword! You fool! You couldn't behead me before! What makes you think you can now?" Tanjiro also thought, "I can't do it with just my arms! I have to slash him with every ounce of strength I have! From the top of my head to the tips of my toes! Use it all! Ignore all the pain in your body! Hang on! Striking with all you might won't be enough! One hundred times the force! Summon it by force!" Tanjiro's muscles and body enlarged as his hair began to spike and grow yellow in colour again.  Another weird thing was that a dark red mark appeared on his forehead as he began to scream even louder than before. Tanjiro's yellow hair also gained a reddish hue on top of it and lost the pupils in his eyes. Tanjiro's blade went into Gyutaro's neck but it didn't go through all the way. Gyutaro started to fear the boy and thought, "Crap! Not by a brat like him! Dammit! I'm about to be beheaded!" Tanjiro's blade went further in as he continues, "No, I'm good! Even if I get beheaded, as long as my sister's head is still intact... First, I'm going to finish this one off!"

-With Zenitsu-
While Tanjiro roared, Zenitsu flew around in the air so fast. Zenitsu thought, "Dammit! I have no more strength!" Daki yells, "I'm going to chop you up into little pieces before you can decapitate me!" Daki sent the final wave of belts to kill off Zenitsu before he could kill her. As the belts were about to cut Zenitsu, Inosuke slashed every single one while Daki thought, "What's he doing here? Didn't my brother impale him through the heart?" Inosuke says, which seemingly replied to her thoughts, "Don't underestimate the flexibility of my body! Shifting the positions of my internal organs is child's play for me! And since I grew up on the harsh mountainside, poison doesn't work on me, either!" While speaking out, blood poured it from his mask. He took a swing at Daki and made contact with her neck. The cloth began to rip as Daki pleaded, "Onii-chan! Do something, will you, Onii-chan?"

-With Tanjiro-
Tanjiro's blade made it further into Gyutaro's neck as he thought, "I have to unleash the Rotating Circular Slashes!"
All three, Zenitsu, Inosuke and Tanjiro screamed in tandem leading up to the final moment of this struggle of a battle. Both siblings' heads were finally cut off at the exact same moment. Both heads soared through the hair with the expression of fear. Everyone dropped to the ground while the heads dropped and rolled to each other's faces. Daki and Gyutaro were right beside each other as they groaned and gasped in confusion.

-In The Background-
Suma, Makio and Hinatsuru were on top of the roof spectating the whole battle. Suma said calmly before it turned to excitement, "They beheaded them. They beheaded them! Beheaded them! Beheaded them! They beheaded them, Hinatsuru-san! Please take a look from beyond the grave!" Makio says, "What the... Do you even know what you're saying?" Suma asks, "What?" Makio slaps her while saying, "Dummy!" Suma responds with an, "Ouch!" Hinatsuru puts a stop to their little one-sided fight and says, "Wait! Something seems off about this!"

-With Tanjiro-
Tengen was lightly gasping but Tanjiro was left heavily gasping for air, having trouble with his breaths. He thought, "Th-The poison... Deal with it with your breathing! S-Slow down the poison as much as you can!" Tanjiro faintly heard Tengen yell out, "Kamado! Get up! It's not over yet!" Tanjiro asked himself, "What? He's saying something. His head... Did I fail to cut it after all? Uzui-san is..." Tengen's voice continues, "Run! This isn't over yet!" Tanjiro finally finished, "...saying something."
Tengen screams, "Run!!" Gyutaro's body released its final attack and destroyed every single thing in its path. The attack was so huge, that it was seen from afar.

Chapter 81: End

-A Little Secret-
Along with Tanjiro's Super Saiyan form (Since they don't know about the Saiyan's SSJ form, I will refer it as 'Super' or 'Golden' in the chapters when more will be released), the mark he achieved helped him reach even greater power than with just his Super form.

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