At first, there had been nothing but vague senses of snow, work, and warmth. Then there had been panic and darkness where there had once been light, but that hadn't stopped the little beings from existing. Then determination and slowly, their world had truly begun to form. An endless blue sky over the calmest of seas. Clouds drifted lazily by above, completing the breathtaking picture. The beings didn't know how other inner worlds looked, but theirs had become so calm and beautiful, despite the pain and anguish they had all felt.

And then there was their sun. The person whom they were a part of called it a soul. It shone so bright and warm in the otherwise cool atmosphere. That was what the beings – guardians? Pieces? Avatars? Whatever they were – wanted to emulate. That warmth and kindness – that joy and hope. The sunlight on a spring day. The lasting rays of a fall afternoon. Something that offered comfort and love. Not too hot, not too cold. Safe.

Then the world had turned red.

It wasn't peaceful anymore… but they held on. The soul changed, but it refused to lose that warmth that had defined it. The sun became harsh and too hot or too cold (or somehow both), but the guardians remained.

And then the blue came back.

But it was tainted. Some of the harshness and desperation (the hunger) from before remained, buried within the sun. Still, the soul almost forgot it and a different desperation took its place. Fear and longing and trytrytry, but it ended in pain. Again.

Then, the taint came back, and took over. The soul lost itself. Then it returned to normal blue again, but with that taint. It happened again, and again, and again, and each time the taint became a little worse, a little more ingrained, but nothing the soul couldn't eventually forget.

Until he was marked.

Until the soul chose to be marked.

When the calm, blue ocean returned after that, the taint was worse than ever, no longer completely buried. The red already worried the guardians (because they were guardians – guardians of the original soul, there to keep that warmth and goodness alive), but this was far worse than they could have imagined or predicted.

And then the soul was marked again. Against his will, but it made the infection all the worse. When the blue came back, they couldn't completely hide the effects of the taint immediately. After that, it simply grew worse and worse…

The sea had long-since lost its utter calmness, and when the red returned that time, it was the worst yet. The despair building within the sun began to eclipse it. The guardians were losing numbers too, one by one slowly dwindling as the soul lost memories of how it used to be. They longed for the reset this time, but when it finally came…

If this kept up, there would be a time when they could not revert to the calm, warm blue at all.

But the guardians were as stubborn as the soul that bore them, and they would protect that warmth long past that time, even if only one of them remained.

The red continued to creep in, growing worse whenever the soul needed extra power – whenever he called on the taint. And it kept changing him. That wasn't the only difference, the taint also felt purer, somehow, but it was still dangerous and damaging. The guardians' numbers still dwindled.

Then the soul – the warmth that had changed so much – did something unthinkable.

It embraced the taint. Reached for it, submerged itself in it, and the sea around the guardians was no longer a sea but the surface of a sun, exploding in flames that were no longer flames but sunbursts and flares. The blue vanished, replaced by red and black, cruel and dark and so, so hungry.

The guardians remained by the core of the soul, despite the warmth being overshadowed by the simultaneous harsh heat and deadly cold. Their numbers started going down again. They huddled together, protecting all the warmth – the kindness and sweetness. As long as they remained, there was hope.

But the world around them wanted to swallow them whole. The sea that had become a sun was no longer friendly or welcoming – it wanted to devour.

They kept it at bay, hoping beyond hope that the reset would happen again – or at least that the soul would regain itself.

But all they could do was wait as they disappeared and the world burned around them.

xXx

Iguro attacked again, growling and screeching. The other demons and slayers dodged out of his way as they tried to coordinate.

"Don't attack him!" Kanroji yelled, her voice desperate. She'd probably been speaking to the boar boy, who looked the worse for wear, but he had his swords out and stood in front of a collapsed Insect Pillar, ready to pounce.

"Then what do we do?!" the kid practically screamed, obviously beyond done and so, so angry. Akatsugi agreed with him. They didn't exactly have options right now. Especially seeing as the Insect girl would randomly attack them too. At the moment, she was literally sprouting wings – the back of her uniform had torn and she screamed in pure agony, clawing at the ground around her and digging holes in the wood. The new appendages looked like a cross between bat and butterfly wings, not fully emerged yet, but he could tell they would be both terrifying and alluring. Typical demon.

Iguro, himself, now had scales all along his hands and arms and his hair had sprouted into a hood. Akatsugi knew that snake. It wasn't from Japan… did the guy have some continental ancestors, perhaps? It might explain the eyes. Demons were almost exclusively Japanese, but Akatsugi had seen a couple that had outside influences.

Was it sad that he found it more interesting than upsetting? Probably.

"I'll lead him away!" Kanroji shouted as she flipped over another one of Iguro's attacks. "I need to find someone with Kamado's blood."

Well, at least she'd gotten off of Akatsugi's back about giving him some of his blood. He'd explained that he'd never been actually injected with Tanjrio's blood. No, he'd become one of the new Progenitor's demons by eating those cells. When she'd asked what that had to do with anything, he'd pointed out that Muzan had injected all of his Kizuki with blood multiple times. That was why they could change people into demons, too. He didn't know if he could turn someone into Kamado's demon, and even if he could, should they take that chance?

She hadn't been happy, but she'd accepted his explanation.

So now it was a matter of finding someone else with one of those pure blood vials or whatever. Akatsugi didn't particularly care. He had to go check on the girl, actually. He only hadn't yet because he didn't want to lead Iguro back up there.

"You want to lead him away?" Akatsugi asked as he jumped lazily out of the Serpent Pillar's attack. Hmm, there were fewer and fewer walkways to land on now. "You sure about that?"

"It's better than having two half-turned demons attacking us at once," she shot back. "Then you two can focus on Shinobu-san."

The former Waxing Third thought about that, then shrugged. Fair.

"Have at," he said.

She nodded firmly, face practically screaming determination.

After that, it only took a couple of calculated jumps for Kanroji to stand in front of the walkway lining the room and wait for Iguro to dive after her. Then she slowly backed down the hallway, waiting for him to follow again, at which point, she turned around and ran.

"Good luck!" she yelled as she shot off down the hallway, leaving Akatsugi, the boar boy and the Insect Pillar behind. Iguro chased her and also disappeared. They waited for several seconds in relative silence before Akatsugi sighed and slumped, then looked around the practically destroyed room.

"She good for now?" he asked the kid.

"No," the Insect Pillar answered herself, but she was coherent enough to answer, so Akatsugi scratched his head as he turned to the corner where he'd entered. Part of him felt elated that he'd beat Douma… but he'd still had help. Then again, he'd defeated the guy without help, but the others had just had to help kill him, which demons couldn't do…

The turnout wasn't bad, really, but it still felt a little… empty.

It also felt good so… he guessed he shouldn't complain.

"Oi, where are you going?!" the boar kid asked.

"To get my charge," Akatsugi said casually as he jumped up through the roof. He found the girl where he'd left her. Good. She didn't look damaged in any way, so she likely hadn't drawn any attention from Iguro. He went to pick her up, but something white jumped out at him and bit his hand. He blinked down at the snake.

"When I said to bite, I didn't mean me," he muttered in annoyance, wrapping the snake around his arm and picking the girl up. Great. He still had to look after the stupid reptile too.

Wasn't he supposed to give it to Kanroji?

Who had just left.

He groaned inwardly, but sighed and hefted the girl over his shoulder before jumping back down. The boar boy knelt by the Insect Pillar while she held his hand tight, tears streaking down her cheeks, whether from pain or… hadn't she said something about revenge? Eh, he couldn't remember.

"Alright," he said as he set the smaller girl down by the older one. "So. Now what?"

"How should I know?" Boar boy shot back.

"You're the demon slayer," Akatsugi pointed out.

"And you used to be a Kizuki."

"What does that have to do with anythin—"

He cut off as something inside of him twisted. He grabbed his chest and at the same time, Shinobu shrieked, the scream reverberating throughout the room. Even the brat's eyebrows drew together and she whimpered in her sleep.

"O-oi! What's wrong?" Boar kid asked, grabbing his swords and holding them up.

Smart kid.

"Something's… off," Akatsugi said, closing his eyes and concentrating. What was that? He forced himself to follow the sudden squeezing sensation back to its origin. It took him a little, but he suddenly realized it was his connection to Tanjiro.

"Off? What do you mean off?" the kid said angrily.

"With… Tanjiro," the demon grit out.

Then Kocho's screams rose in volume and those wings burst from her back in a display of pastel and muscle, claws at the edge of each finger snaking through the wing. Her teeth and claws… she looked like a fully realized demon – or very nearly so. That had been.. sudden. Too sudden… just what was going on?

No… wait, he'd felt this – or something similar – before. When Muzan got angry. It didn't happen often. The guy was always displeased or annoyed or upset, but he rarely got truly angry. And the last time that had happened…

Kizuki had died.

Oh, this was not good.

He'd known Kamado was too good to be true. He knew the kid had been hiding a darkness, but this? It felt worse than Muzan! Or was that just his imagination? Was it the comparison to the kid's normal demeanor?

And why did he feel so much hungrier all of a sudden.

"Kid, you better run," he gasped out.

"What?!" Boar boy asked, "I ain't leavin—"

"I'll take care of them… but I ain't sure I can stop myself from attacking you right now. So get out, and take this," he shoved the snake at the kid, who fumbled for the creature, but caught it. Then he stared at it for several seconds, the reptile obviously damaged and unhappy, but alive.

"You want me to—" he started, but once again, Akatsugi cut him off.

"GO!"

The boy frowned at him for far too long (and he was smelling better and better… not good) before setting his jaw firmly. "Fine! But I ain't runnin' away! You got me?"

The former Kizuki didn't really care at the moment. "Yeah, sure, kid. Just… hurry."

The boy draped the snake around his neck, then grabbed his swords, turned and stomped out. "You better take care of her! Got it?!" He yelled, and then he disappeared.

Akatsugi snorted.

Then a blur flew by him towards the door the kid had just left through. Kocho.

He managed to catch her, but just barely. Oh, she was fast. If she was that fast as a newly turned demon...

She turned to screech at him, but he roared at her, baring his teeth. She seemed taken aback by that but still backed down… from him at least. Good.

But then she took off towards a pile of bodies on one of the walkways, all women, all dead, all either half submerged in water or half lying in their own blood on the broken wood.

Oh. That smelled good too.

But, no.

He managed to reach Kocho before she got her claws on one of the bodies. She struggled against his grip, but he forced himself to turn and stomp away through the water, dragging her with him.

"You'd hate me if I let you," he said with a sigh.

Seriously, why was it always him? He wasn't good at taking care of people. He thought that had been proven.

"So we're gonna go find some more demons," he assured her. That sounded good right now. "Then you can have a ball."

He scooped up the smaller brat too, and draped her over his shoulder again. She still seemed to be having issues herself, even in sleep.

Seriously, what had happened to Kamado? To Tanjiro?

He'd have to find out later, he supposed.

Grumbling to himself, he stomped down the hallway opposite of where Kanroji, Iguro, and the boar brat had disappeared.

(He'd better find out later. And he was gonna find a way to beat some sense into that boy if it killed him for all of this.)

Kamado had REALLY better appreciate this.

xXx

Gyomei didn't quite know what to think about the situation he'd found himself in. He could hear the two demons in the hall (three if he counted the one on the floor) struggling, presumably as one of them held the other… As Shinazugawa held Kaigaku.

He'd known the boy had been picked up by the former Thunder Hashira. He hadn't known what to think of that when he'd heard of it, to be honest. Eventually, though, he'd written to both Oyakata-sama and the Thunder cultivator about it.

The latter had responded that he appreciated the information but had made his choice and to kindly stay away from the boy. Oyakata-sama, who had already known everything, had simply said he would avoid putting Gyomei and Kaigaku on the same missions if at all possible.

Gyomei had suspected he'd have to cross paths with the boy eventually but… not like this.

"Can he speak?" he asked, unsure of what he wanted the answer to be.

Shinazugawa grunted. "Don't think so. He doesn't like you much."

"Shinazugawa-san! It looks like he wants to run away from Himejima-san in fear!" Rengoku said boisterously.

That… surprised Gyomei… but more, it hurt. He didn't think it should hurt after… after everything. Oyakata-sama had explained what happened after sending some slayers to question everyone involved in the incident that had thrown him head-first into demon slaying. Perhaps that had been how Kaigaku was recruited too? He didn't know but… he didn't find out until much later, either way.

Kaigaku.

Part of him didn't want to have anything to do with the kid. Part of him wanted to be grateful because he had grown so much since then and he wouldn't have otherwise… and part of him still wanted to make sure the boy was alright – still considered him to be one of his children.

Before he could say anything else, though, Kaigaku shrieked. No, he screamed. In what sounded like pain. Agony. He could also hear Shinazugawa grunting, as if trying to hold something back.

"Rengoku?" he asked quickly.

"They seem to be hurting… and black veins have become visible on the boy."

That third part of Gyomei won out and he went to step forward, unsure of what he could do but wanting to do something.

"Don't!" Shinazugawa growled. "Something's… wrong."

"What is it?" Rengoku asked. "You seem to be in pain!"

"Just go… want to… attack… you."

Oh, that was not good.

"We could kill you!" Rengoku said. Himejima's heart tore that much more at the idea of losing his friend and one of the few children he had left, even if he was beyond angry at the boy. Still. He thought he'd gotten rid of that a while ago. It looked like he'd be spending some time under waterfalls in the near future… if he survived. Some cold meditation sounded very appealing at the moment.

"No!" the white-haired demon said. "Just… wait it… out. Go!"

"Shinazugawa," Gyomei started.

"I'll take care of them, now go!"

"Himejima-san," Rengoku said quietly for once, putting a hand on his arm. He didn't want to leave them but if it would help them to regain themselves…

Gyomei nodded and turned, hurrying back the way they'd come, then taking off down another hallway they'd passed as he tried to block out Kaigaku's (his traitorous child's) shrieks behind him.

It didn't work.

xXx

"How are you doing, Genya-san?" Zenitsu asked, noticing the boy's jerks and how tenderly he stepped. Like every footfall caused him immense pain.

Genya shot him a glare over his shoulder, one Zenitsu flinched away from, almost falling back into Kanao. "I'm slowly turning into a demon. How do you think I'm feeling?"

Well… he didn't have to snap like that, did he? Still…

"S-sorry," Zenitsu muttered petulantly. Genya rolled his eyes and looked ahead once again. They'd had no luck finding Kaigaku. They also hadn't found any other demon slayers, or a way out yet. Zenitsu had gone beyond worried. Where was Inosuke? Or that Pillar guy? And why were they creeping around behind a transitioning demon slayer who couldn't seem to walk faster than a snail's pace? Not that he could blame the guy. It looked like his body was kind of twisting in on itself and—

Suddenly, the kid froze. Behind him, Zenitsu heard Kanao withdraw her sword. He refused to do the same. Genya had been the reason why they'd been able to defeat Waxing Five.

"Genya-san?" he said slowly.

"Something's… wrong…" the guy said.

Zenitsu exchanged glances with Kanao.

"Wrong?" the Storm breather began. "What d—"

But before he could say anything else, the taller boy screamed and hunched over.

"Genya-sa—" Zenitsu started, stepping forward, but a hand on his arm held him back. He looked over his shoulder to see a grim-faced Kanao, her eyes fixed determinedly on the demi-demon. The blond turned back to Genya just in time to see the guy's back bulge. He grew even larger, if anything, and sprouted fur down his spine – thick clumps that stuck out messily in all directions.

"We should kill him," Kanao said.

"No!" Zenitsu refused.

"He's becoming a demon!"

"We know plenty of good demons!" or, well, two, but still!

"He—" she began, but Genya turning on them, looking like some cross between a bat, a wolf, and a human, stopped her. He roared at them, but didn't attack.

"I… think we should run," Zenitsu squeaked out.

Kanao didn't seem happy with that. Reaching in her pocket, she took out a coin. Zenitsu couldn't help but be incredulous as she flipped it, all while Genya looked like he was fighting himself… probably deciding whether to come after them or not. When the coin landed and she looked down at it, she 'tsked' but put it away and then met Zenitsu's eyes.

"Run."

He almost cried in relief. Okay, he may have actually cried in relief, but who could blame him?

"Go!" he said, turning and urging her ahead of him. They did so, shooting down the hall. Not seconds later, they heard the shriek of an unearthly howl behind them and ran even faster.

Just what was going on?

xXx

AN: Sorry guys, no actual Tanjiro pov this week. We needed to catch up with everyone else. But there is Tanjio fanart on my AO3 page. :) FYI

Thank you to Found and Quathis for their help on this!

Discord: discord. gg/xDDz3gqWfy (no spaces)