I don't own Dragon Ball, Kimetsu No Yaiba and Doctor who. Dragon ball is owned by Akira Toriyama and Kimetsu No Yaiba is owned by Koyoharu Gotouge.
Last time Cybermen invaded and Goku and Vegeta easily beat them but one got away. Goku and Vegeta comfort Muzan Kibutsuji. But at the sound of a musical instrument Goku and Vegeta have been separated.
Chapter 6: the end of Demons:
Goku and Muzan stare each other down. Goku makes the first move landing a punch into Muzan's chest and lands more punches. Goku is surprised at how quick Muzan is healing. Goku says your weak not even worth fighting I don't know how the Demon Slayers struggle to beat you. Muzan says don't underestimate me. He transforms and now has a lot of tentacles with teeth on parts of his body.
Vegeta is getting teleported at the sound of the instrument. Vegeta manages to find the demon and blast it. Vegeta manages to get the demon and throw him in the air and goes galick gun! Which kills the demon which causes the building to collapse. Goku and Vegeta shield themselves with a Ki barrier. It's night time luckily for Muzan. Goku goes what mouths with teeth over his body with lots of tentacles. Muzan attacks Goku dodges with ease for the moment. Goku gets hit and cut. Goku starts to feel bad. Muzan says I got you with to much of my blood now how cells will be destroyed like a poison. Goku thinks (dammit poison affects us Saiyans quicker than humans.). Vegeta don't get hit. Goku lost himself. Muzan says wait a minute your cells should be getting destroyed. (How is he turning oh wait they aren't human that could be why I need to get more blood in him to kill him. Nope I am going to let him turn into one and he can deal with his friend.).
Goku hasn't changed Muzan is surprised that Goku is attacking him and not Vegeta. Muzan shouts how! Goku says sorry I guess turning a Saiyan into a Demon works way different than humans and I am already dead. A halo had appeared over Goku's head. Goku says no need to hide the halo anymore I guess. Vegeta says how can you be here with the halo above your head Kakarot? Goku says it's simple even when dead I can be in this world in other dimensions but not at home. Goku says plus I had a senzu bean. Right I guess it's now time to end it once in for all you monster! Goku goes solar flare times hundred. Muzan is caught in the blast of sun light and dies. Goku says it's over. I wonder if the doctor can get the Dragon Balls I want to do a kind wish. Vegeta says and what would that be? Goku says well I aren't saying it's a surprise for Tanjiro and Nezuko. Goku says but first I am going to go around and finish any demons who survived Muzan's death.
Goku uses instant transmission and returns after making sure there's no demons left. Goku makes sure that Tamayo and Yushiro are the only two demons left in existence. Goku goes to the Doctors and asks them to get the Dragon Balls and return with them. The 13th Doctor goes to the Dragon Ball Universe and gets the Dragon Balls and returns to the Kimetsu No Yaiba universe with them.
Goku gets Tanjiro and Nezuko and they enter the Tardis. In the Tardis Goku summons Shenron. Shenron says I am the eternal dragon state your wish. Tanjiro and Nezuko both agree on a wish. Tanjiro says I wish that my family that was killed back to life! Shenron goes your wish has been granted. The Dragon Balls go into the air and disperse. Lucky they didn't get far in the Tardis so collecting them again was quick.
Tanjiro and Nezuko step out of the Tardis and are greeted my their mother and younger siblings. Tanjiro goes I don't know how to thank you Goku you did so much. Goku says no problem okay Doctor you can now take me and Vegeta back home now. The 10th and 11th Doctors before they leave say good to know that my future is in safe hands to the 13th Doctor. Emily appears and she thanks Goku, Vegeta and the Doctor. Her time has ran out and Emily fades away.
Because of Goku, Muzan and the demons are no more and the Demon Slayer Corps is disbanded. Tanjiro and Nezuko thanks to Goku go back to their normal life's since they family who Muzan killed was bought back by the Dragon Balls.
Everyone lives their new life's with happiness not having to worry about demons anymore. The happiness ended with World War Two though. Most of them died. Nezuko still remembers her past demon life and smiles. Nezuko got a job has a nurse.
Tanjiro and Kanano did meet and Tanjiro made her start following the voice in her heart. They both end up together and later down the line get married and have kids. Nezuko feels happy for them and so does Shinobu.
Nezuko has met Zenitsu who keeps on bugger her. Nezuko manages to make Zenitsu calms down. Zenitsu apologises to Nezuko. Zenitsu ends up being useful helping Nezuko take care of patients. They end up together and have a kid of their own.
The rest of the family has also started running a bakery. But Kie sadly dies to a disease. The dance of the fire god still got passed down through the Kamado family for generations just encase.
Everyone dies of old age eventually having lived a peaceful life. Even the pillars future families too all thanked Goku and Vegeta through the generations.
The end for the Kimetsu No Yaiba universe.
In the Dragon Ball Universe the Doctor drops Goku back at King Kai's and Vegeta back at capsule Corp. Years pass peacefully until majin boo.
The 13th Doctor goes right where to next. 10th Doctor goes okay so what's next.
The End
(A/N)
Okay that does it for this story. But it's not the end yet for the 10th and 13th Doctors since they end up in a different Kimetsu No Yaiba timeline with another version of Goku and some things that end up from two different the futures 2034 and 2046. Also the Dalek and Cyberman both have ended up also in that timeline. The five way crossover. So this actually is the end of this Kimetsu No Yaiba timeline. Oh yeah I forgot to mention that last chapter Emily is a character I made up myself. And that she appears in the other three stories. I rather make all of the chapters for the other two stories first before I upload them so I can have them ready with less mistakes.