Hinokami
Sasuke wakes up from his daze. His eyes are slowly regaining their vision. He sits up carefully and observes his surroundings. It looks as if he is in a huge sky, whose reflection is reflected on the thin surface of the water on which he lies. After Sasuke sat up properly (even with effort, using the one arm he has), he saw a person standing in front of him.
The person, or rather the creature, looks like a human. The face is covered by a cloth with fire written on it in kanji and the robe it wears does not reveal the gender. It has long, fiery red to ash-black hair that looks like flames and is tied into a braid that ends just below the waist. The robe consists of a large black poncho with a red fire pattern on it. From the waist up it is held by a band on the hips and the rest of the material hangs loosely. There are sunny yellow fringes at the end of the poncho and on the wide sleeves. It also wears loose white pants and no shoes.
It just stares at Sasuke and stays in place. Sasuke stares back, not really knowing what to do. He doesn't feel threatened in the least, but rather reassured. He stands up, his gaze still on the creature. After he stands up, he starts talking.
“Greetings, Sasuke Uchiha,” it said in a particularly calm voice. Sasuke stayed calm and tried to find behavior patterns through the strange human being's demeanor that would help him find out more about the situation.
“Hello,” Sasuke greeted back carefully but in a calm voice. “My name is Hinokami. I am the fire god from another universe. There’s a little so-called pest problem in my universe right now.”
“Pest problem?” asks Sasuke incredulously. He still didn't know where he was or why he was here, but the creature in front of him didn't radiate any hostility. So the Uchia decides to stay calm and alert.
“Exactly,” says the creature. “What does this have to do with me?” asks Sasuke.
“I ask for your help with my pest problem,” the god says calmly and waits for Sasuke’s answer.
Sasuke really wonders what he should help with. He doesn't have anything to do right now anyway. He left Konoha a few days ago and said goodbye to Sakura and Naruto. After the war, he was also cleared of his previous crimes by the Sixth Hokage, Kakashi Hatake. But if he now disappears without a trace, to help another universe - however that works, he can enter other dimensions with his Rinnegan, but universes? - it's rather suspicious that he's suddenly gone.
So Sasuke decided on the most logical answer "I can't help you with this problem, if I disappear from my universe now, it could be suspicious."
Sasuke watched the creature closely. Whether there would be signs of frustration or expectations, but he found nothing. The creature just stood there.
“That won’t be a problem,” says It. “Time passes differently in your universe. 1 year in this universe is 1 day in yours. That shouldn’t be a problem.”
A year there is a day here, Sasuke thought. “Well, it seems like you don’t want to or can’t force me. So, how can I help you with the pest problem? And how does this universe work? It can't be exactly the same as the one I'm in. Otherwise you wouldn’t need my help.”
“Exactly,” It replies in a calm voice. “I can’t force you and I don’t want to.”
“There have been demons in my universe for about 1,000 years now. It's a simple concept. A demon king who leads the demons and demon hunters who hunt these demons. They are normal people, but they use breathing techniques and sword techniques to win against the demons.”
The god takes a short break to make sure the human comes with him. After collecting his thoughts, Sasuke nods to show he's still listening.
Hinokami - as the god introduced himself - continues speaking "Your task will be to become a demon slayer and help kill the demon king, Muzan Kibutsuji."
“Won't it be noticeable if some guy shows up out of nowhere to help. Without any experience in the aforementioned sword and breathing arts.” Sasuke asks with an incredulous tone.
“You will be transported back into the body of your twelve-year-old self, of course you will retain all your memories and even your abilities. I have managed to ensure that you can also use your chakra in my universe,” says the fire god calmly. “I will drop you off near an older member of the Demon Slayer Corps. He will teach you everything you need to know. Once your task is completed, you will return to your universe. Just like I picked you up there.”
Hinokami makes the human think about his answer. It is still where it was at the beginning of the conversation.
Be transformed back into my twelve-year-old self? Sasuke thinks in disbelief. But he would be normal again when he was back in his universe. But before he accepts, he has one more important question. “What happens if I die in this other universe? Am I then also dead in my universe?”
“You end up here again, I will then take you back to your universe,” says the creature reassuringly.
I'll only be gone for a few days and nothing will happen to me physically, thought the Uchia. "I'll help you with your pest problem," Sasuke decided finally.
“Thank you very much,” says Hinokami, leaning forward slightly to show his gratitude. “It might tingle a little now.”
Suddenly a bright light envelopes the Uchia. His eyes close in response to the light and his body assumes a defensive position. Sasuke then hears the God say “We’ll stay in touch”. Then everything turns black.
==- Mount Sagiri -===- Sasuke POV -==
Sasuke regains consciousness once again. He lies in a forest. The forest is large and the trees are sometimes close together. Plus it's snowing. As the god said, Sasuke is back in his twelve year old body. He wears a traditional Japanese robe from the 1900s, along with a dark blue kimono with the Uchia symbol embroidered on the back.
After collecting his thoughts, Sasuke stands up. There must be a house or a village somewhere around here. The creature said an old member of this corps is here, Sasuke thought. So he started looking for this member, also he has to keep moving otherwise he will freeze in place.