Somewhere in a library.

"Finally, there's no need to search for the blue spider lily. A demon who can withstand the sun has appeared. I do not need you anymore." said Muzan killing the 2 maids.

"If I can absorb and eat that girl, I can actually defeat the sun." Muzan grinned Manically.

Butterfly Estate

"It seems everything is well, Shinobu?" I questioned.

"Yes everything is well but you still had a few scratches." said Shinobu with annoyance.

"Sorry, I couldn't avoid it. I only passed out because I used up all my stamina." I replied.

"Yeah,yeah. That mark, it's similar to Tanjiro's mark. What does it do?" questioned Shinobu.

"When it appeared, I gained more strength and I was able to see everything in slow motion. Something like an ability the mark gives? But it seems the mark disappeared when I passed out." I replied.

"How did you awaken it?" asked Shinobu.

"A demon was about to kill Mitsuri, I was desperate to save her then it happened." I answered.

"So it awakens when you're desperate for something. Did you know, after you passed out. The area where you passed out, started to grow ice and freeze? It was like real ice." said Shinobu.

"Eh?" I said in confusion.

I didn't know how to answer that, I never thought something like that could happen.

"Looking at your confused face, I guess you don't know what happened. Don't worry, Ubayashiki-sama waved it off. The ice had already melted because of the sun, but for some ice. It sure did take quite a while to melt." said Shinobu.

"Ah, sorry for the trouble. May I go visit Tanjiro and Nezuko? I'm able to walk." I said.

"Sure, don't overexert yourself or I'll personally kill you." said Shinobu with a smile.

She really would kill me, I could tell by her aura.

I walked into the medical room where Tanjiro and a kakushi was talking.

"Oh I see, they moved the village." said Tanjiro.

"It's fine, we've made a number of dead villages so they can live there. You've been out for 7 days, you okay to eat?" asked the Kakushi.

"Yeah! Kanroji-san said to eat a lot." said Tanjiro.

"That person seems a little weird though, apparently the Love Pillar slept for two days and was at full power. I heard the Frost Pillar was even weirder, she woke up in 3 hours and was at full power." said the Kakushi.

"I guess I am pretty weird." I said,

They both looked startled by my sudden appearance when they just noticed I was there.

The kakushi suddenly got into a dogeza position and started begging for forgiveness.

"It's fine, I receive those comments quite a lot." I said reassuring the kakushi. He seemed to calm down a bit.

"Hello Tokan-san! It's good to see you." said Tanjiro.

"Same, I heard about your sister Nezuko. Is she doing well?" I asked.

"Oh yeah. She can walk in the sun now!" exclaimed Tanjiro.

"I see." I replied.

"Isn't that like really bad? What's going to happen now though? What the heck's up with your sister?" asked the kakushi.

"I don't know, they're looking into it." said Tanjiro.

"It seems the Tamayo person is looking into it." I said.

"Tamayo-san?" questioned Tanjiro and started choking.

He recovered thanks to the kakushi giving him water.

"And where the three little girls?" asked the kakushi.

"Aoi-chan isn't here either." said Tanjiro.

"None of the hunters are in serious condition. I think I saw them play around with Nezuko when I was coming here since she's able to speak a bit. That yellow hair boy seems to have encountered her." I said.

"GYAAAAA!" a scream was heard through the halls.

"Message! Message! Ubayashiki-sama ordered an emergency Pillar Meeting!" said my kasugai.

"It seems I have to go. It was nice speaking to both of you." I said as they both waved me off.

Ubayashiki Mansion.

"I envy you guys dammit. Why can't I run into upper demons?" asked Sanemi.

"It's not like I run into them all the time. But how are you doing Kanroji, Tokitou, and Furoku?" asked Iguro.

"I'm fine." I replied.

"Oh yeah! I'm feeling a lot better now!" exclaimed the cheerful Mitsuri.

"I'm not at full strength yet." muttered Muichiro.

"If we lose any more pillars, the demon slayers will be in trouble. But defeating 2 upper demon moons is quite noble." said Gyomei.

"You three recovered quite quickly from this, did something happen?" asked Shinobu.

"Oyakata-sama probably wants to talk to us about everything including this." said Giyu.

"Sorry for the wait, I Ubayashiki Amane, will attend the pillar meeting in place of Ubayashiki Kaguya." said Amane

"Right now, the disease affecting our master Kaguya has gotten worse. He sends us apologies for being unable to attend the meeting with you all.

We all positioned towards Amane as Gyomei prayed for his health.

"He would like to give his thanks to the pillars. I'm sure you've known this but we have a demon who could conquered the sun and she is here. Muzan has probably altered his goals and most likely go after all. So that he can conquer the sun himself, the time for an all out battle is approaching."

"And we have reports of strange marks appearing on Kanroji, Tokitou, and Furoku during their battles against the upper moons. So I would like to ask you all how you obtained them."

Tokitou and Kanroji looked shocked this, but I already knew.

"Furoku, it seems you already knew." said Amane.

I nodded.

"During the Sengoku Era, there were swordsman of the first breath who were one step away from ending Muzan. They all had marks that resembled demon crests. The knowledge has been passed down though, some people should've heard of this." said Amane.

The pillars were quite shocked.

"I haven't heard of this, why are we hiding it?" questioned Sanemi.

"Because people who were brooding over marks never appeared, and that's why a lot of information has became hazy to me. But we do have one piece of information, once one person with a mark on them appears. It starts spreading to others." said Amane.

"That was howone of the swordsman of the first breath put it. And as of now, the mark has never appeared on one of the pillars but Kamado Tanjiro. We asked him how but he had trouble explaining it. So pleasure inform us how it appeared." asked Amane.

"Okay! My body was super light! It was like badaam and durrr then budaah! Then my heartbeat went badum badum and my ears went scree and tinke tankle too!" Mitsuri cheerfully tried explaining.

We all looked at her deadpan in the eyes and groaned in frustration.

"I'm sorry I'll go hide in a hole now." said Mitsuri in a dogeza position.

"All I know was I was desperate to save Mitsuri." I said and Mitsuri gave a smile as bright of the sun.

"I wasn't aware of any marks, but I became aware of a number of different things. If you fulfill these conditions, maybe everyone will get the marks. Let me tell you the information." said Muichiro