The True Demon King

The final selection

Soon after I woke up I saw Nezuko and I was relieved but I did not know how he knocked me out. Wait, that sword is specified for demons so it weakens the demons because their necks are as hard as steel so you have to have a strong will and strength. I head out and take nezuko with me and I keep her in a box of bamboo thing to keep her from the sunlight. I saw a demon when I was near the spot I was supposed to go but I only had my ax he tackled me to the ground but thanks to nezuko kicking his head off but I know that would not kill him and his body was moving so I hid him three times on the head with my head then threw him while he was clung onto the ax and the sun started rising and he just burned away then a man with a weird mask on came out and said
"Well you did ok for the first demon you have killed but you can't be soft when it comes to killing demons or they will kill you, but I assume Tomioka sent you since you're here?"
I reply
"Yes he did, are you mister sakonji, and the person who will train me to become a demon slayer?"
He nods at me and he starts walking away and so I follow close behind him

Time skip Two years later

I cut the rock. He was surprised I was able to do it but he let me go to the final selection. I had gotten to the location and I saw a lot of these pretty flowers but they were kinda affecting me because I know they were a type of tree poisonous to demons and I was one of them but my dad taught me how to not show I was affected so I just calm down and defeat demons that just came running at me but then I saw the demon that killed sabito the one who helped me and the girl to so I start fighting he was pretty good but I could smell that he was trying to attack from under I jumped and while I could doge mid-air I did not show it I blocked his attack but he flung me across the place and I hit a tree. I was knocked out for a short time due to me not having a strong physical body but then I saw my mom telling me to get up luckily I had dodged just in time I ran un the arm he had created and sliced his head off I saw his hand being held out like it wanted to be held so I grabbed his hand with both of mine and he thought to himself
"I just tried to kill him and he's being nice to me a demon is he not supposed to be a demon slayer"
The demon soon starts remembering his past humanity and starts crying and then burns away from the world he used to call home.
After what happened only a few people remained a blonde kid that looked terrified a black-haired guy who had a lot of scars on his face and a girl with a butterfly in her hair who looked calm. Two girls who looked to be twins started talking simultaneously and then the black-haired male went up to one of them while grabbing her by the hair and saying
"Where is the sword give me the sword NOW"
I started grabbing his hand saying
"Let her go she will get to that point soon so please calm down"
I started gripping his hand and he lets go soon after I ask in a concerning type of tone 
"Are you ok Miss I hope he did not injure you may not know him but I apologize for his behavior"
She looks at tanjiro and says
"I'm alright, but I do thank you for your concern sir"
I started heading down after that she begins to tell everybody to pick one of the many metals for the sword everybody goes up, and I'm last I start smelling the air, and I picked one everybody starts leaving I stay behind to talk to the girl that the black-haired male tried to hurt. Tanjiro goes up to the two females and bows once again but this time they are both shocked how he is bowing once more the twins start saying
"Thank you for coming and I hope you have a nice day we will soon contact you about your sword and your missions"
Tanjiro starts saying
"Ok thanks for telling me this I hope you have an equally good day, and I hope we meet sometime in the near future"
I wave goodbye and so do the girls soon after they go to the main household and tell the master about the new demon slayers. The master could tell something was up when they mention the black hair male named Genya Shinazugawa and the kind-hearted male Tanjiro Kamado the master begins to ask
"What happened during the end of the test?"
They both start saying
"The black-haired male grabbed one of us by our hair and this very king man helped us and even apologized for him even when he did not know him"
The master is shocked but still had the words to say
So this boy kamado Tanjiro protected you and even apologized for somebody he does not know he sounds very nice I hope to meet him in the future."