Demons Among Slayers? (Male Demon Reader x Kimetsu No Yaiba)

Helping The Enemy?

Mild cursing, and quite a few timeskips ahead. I apologize.

Y/N POV

I've been stuck in this cave for 3 hours. I can't leave because of the fucking sun, I can't sleep because I'm not tired, and the sun rays keep inching closer and closer into the cave. You could say I'm "fucked".

Just 6 more hours, and I can get out of this hell hole.

*2 hours later*

It has now become apparent that will most likely not leave this cave. The sun has now covered slightly more than half the cave.....fuck.

*3 more hours later*

I'm now sitting in a tiny corner of the cave, the rest is pretty much covered by the sun. I could try and run out but I'd need to find a tree or maybe a large rock to find any shade... It'd probably take about 5-10 seconds for the sun to kill me.

*15 minutes later*

I no longer have a choice whether I'm going to leave or not. I have to or the sun will kill me. The spider family's home should be aroung 30-50 feet to my right.....But can I run that fast..fuck it.

I drink about 50% of the blood I got from the man from yesterday. And with one final push, ran out into the sun. The sun's effect was slightly delayed due to my hooded cloak, it only gave me an extra 2-3 seconds, but I'll happily take it, I broke into a full sprint, running as fast as I could to the spider fam household. But was surprised when I arrived in less than 6 seconds. I crashed through the door, and was then greeted by the spider family. The father looked disappointed, the sister looked worried, the brother looking smug, as usual, the mother looked surprised, and Rui, was furious. wasting no time, he jumped forward and tried to slash me with his threads, but I swiftly dodged them and ran away as fast as I could. as much as I wanted to, I cant win if I fight like this.

*40 long minutes later*

I had been running around the house, trying to avoid the family, but I noticed the moonlight shining through a window. "About time." I muttered to myself as I jumped through it, and ran into the forest. It was weird though, halfway through our little game of hide n seek, its like they stopped trying, or they disappeared. I didnt really care, since it made everything much easier, but it was still really weird. As I finished my thoughts, I heard the clashing of what seem to be a sword? Running further, I saw a boy in a yellow haori with slightly lighter  yellow triangle patterns fighting one of the spider demons. 'So that's why they left.' I run in, and stomp on a few of the spiders before running off. Also taking  notice of the boys unconscious state. 'How the hell is he fighting like that?!?!?!'

I then came across another boy, except he was wearing a green and black checkered haori, fighting Rui...I was going to leave him alone, but saw that Rui was about to kill him. I also noticed the young girl hanging above them, being held VERY tightly by Rui's threads. For some reason...that angered me. I lunged at Rui and kicked his side, before grabbing his leg and throwing him a good distance away from me and the boy.

"Are you ok? Can you still fight?" I asked the boy, without taking my eyes off the lower moon a few yards infront of me.

"Y-yes, I can still fight. Thank you for saving me!" The boy quite loudly but enthusiasticly said.

Tanjiro POV

I was about to be killed by lower moon 5, but this person came and saved me....but he smelled...like a demon? Why would a demon help me fight another demon? From the way they're looking at each other, and the smell of anger coming from both of them, it seems they know each other, But they dont like each other. I readied my sword. I hope he's here to help, because I know I can't beat this demon alone, but to fight them both would be suicide. As I started to breath, the boy glanced at me, almost studying what I'm doing, then said "I can't kill him, so I'll leave that job up to you, but I can hold him off while you wait for the right moment to strike." I give him a nod, agreeing with his somewhat risky plan, because I didnt really have a choice. This is my only option!