Akatsugi walked through a forest. Or… he glided? Floated? He wasn't sure. His feet didn't feel like they were moving and yet…

The trees stopped rather abruptly. One moment he was surrounded by them and the next, he stood in front of a treeline. Looking up at the mountains on the horizon, he could see the first rays of sun beginning to peek over the edge of the not-so-distant peaks. They had maybe fifteen minutes until dawn.

He remembered when that used to scare him.

(He didn't like to admit that it still did, a little.)

Movement caught his eye and he looked over to his right. A train lay derailed, many carriages tipped over on their sides and people crawling all over them, trying to get others out of the downed cars. That wasn't the movement he'd initially seen, though.

A fight had caught his attention. A fight between a demon and a Pillar…

And then his eyes widened. He saw… himself. Or, well… Akaza as he'd been under Muzan. And he was fighting… Rengoku? It wasn't a spar either. They were fighting to kill. A little ways behind them knelt Kamado Tanjiro… but not the one he knew. This boy had large, burgundy eyes that matched his hair, flat teeth and a look of absolute horror on his face as he stared at the battle playing out before him. Someone – a human, he realized – stood beside him with a boar head over theirs.

Well, he'd seen stranger demons so he ignored the figure for now.

His eyes focused back on the fight itself and he leaned forward, wanting to rush in and do something, but unlike earlier, even though his legs moved, he couldn't seem to get any closer.

His other-self's fists flew in a blur as he punched at lightning speed. Rengoku met him match for match, but he was already bleeding and tiring.

Akaza kept yelling out, telling Rengoku to become a demon so they could fight forever! Rengoku refused every time. Akatsugi wasn't surprised. This was very similar to the Rengoku Kyojuro he knew.

And then, after one final charge, the Pillar cut his opponent… but it wasn't enough. In the same motion, Akaza punched right through Rengoku's gut. For several seconds they just stood there as the Waxing Third gave him one final, desperate offer to become a demon. Instead of even answering, Rengoku (Akaza kept calling him 'Kyojuro', but Akatsugi seriously doubted he'd been given permission to do so) still managed to get in another enormous hit, trying – and very nearly succeeding – to cut off the demon's head at his neck. When his past (other?) self tried to stop the Pillar, said Pillar let go of his sword with one hand and caught his fist.

'How can he still swing his sword?' Akatsugi asked himself. He'd known his… ally? Acquaintance? Friend? Was amazing but that determination… wow.

The horizon lightened even more. They had minutes… seconds even, until sunlight hit them. For what felt like forever, the two of them stood there in a stalemate, Rengoku seemingly determined to keep Akaza in place as Kamado and the boar-headed boy rushed forward to take his head. If his past self hadn't ripped his own arms off, he would have either died by the others' blades or with the sunlight… that was, of course, if Rengoku hadn't managed to actually chop off his head first.

Akatsugi turned his focus to Kamado as he rushed forward, angry and determined. He'd seen similar expression on the Kamado Tanjiro he knew, but there was something different about this one, besides the obvious. Something… purer? No… something… freer, he thought. And happier. Not as weighed down… more innocent… more hopeful.

It really hit him then: this wasn't the Kamado Tanjiro Akatsugi knew.

It was amazing how much of a difference those little details made.

Akaza ran off into the forest, right past Akatsugi. The demon from the memory didn't acknowledge the onlooker. Kamado followed, stopping at the treeline a foot away from Akatsugi. Without even missing a beat, he threw his blade at Akaza's retreating back. It struck home but… didn't do much damage, despite piercing Akaza through. The demon kept running while Kamado screamed about how Rengoku had won, not him and how much of a coward he and all demons were for running and only fighting at night.

Meanwhile, behind them, sunlight warmed the area around the train. It wouldn't be long before the sunbeams would get to the arm still inside Rengoku, holding his blood and other bodily fluids in. Once that happened, it would dissolve and he would most likely bleed out.

Akatsugi felt sick.

Kyojuro managed to say some things to the remaining demon slayers, including Kamado, but Akatsugi didn't know what it was. He didn't want to know. That… was private. Instead he turned from where he stood in the sunlight, staring into the forest after his other self.

Kamado was right. Demons were cowards. That was how they won. That was how they lived. Fighting, killing, eating and then hiding from the light. They were forced to be cowards, in a way.

And Muzan was the biggest one of all.

Akatsugi's eyes opened to the plain, dark room he'd been given and he sat up, dream still fresh in his mind.

No… not a dream, a memory. It didn't take enormous brain power to put everything together.

So, he had been the one to kill Rengoku in Kamado's first life.

He felt guilty over it, even though he hadn't really been the one to deliver the final blow. Killing Rengoku who had, in this life, been far more accepting than most Demon Slayers, even going so far as to teach him his breath style…

What a waste.

(He wasn't entirely sure what had been wasted, but he was positive Akaza had seen it too. That had been why his other self had kept asking Kyojuro to become a demon.)

Akatsugi turned, looking out the window at the rising sunlight beginning to shine through the trees, just barely touching the windowsill. He held up his hand as if to catch a sunbeam, watching it shine on his palm for a couple of seconds before letting his hand drop. He looked down at his skin, studying it. It didn't even turn red anymore.

He let his hand fall the rest of the way to his lap and glanced around the room. His room, and his alone. At the Ubuyashiki estate. He wasn't even guarded anymore.

He found it both amusing and a little sad that what he currently had was so much better than anything he'd ever found under Muzan. The people here demonstrated that they were growing to trust him every day, and… he wanted to return that. It was a… strange concept, and more than a little uncomfortable (often he found himself… not running from the other occupants of the estate, but definitely avoiding them, as if he should fear them, as ridiculous as that sounded – he'd always make time to confront them later, though; he wasn't a coward). It was more than he'd ever had under his old master. More encouragement, more resources, more time…

Less eating, and he had to earn his freedom, but it was really a small price to pay. The freedom he had and was earning far exceeded anything Muzan would ever consider giving to him.

Should he talk to Kamado about these dreams? He didn't really want to. Maybe he could just focus on training with the kid. After a minute, he nodded at his conclusion. He would focus on helping Kamado get the hang of absorbing his flesh and regrowing his limbs and worry about dreams and such later (if ever).

That thought brought up his memory of the evening before, watching Kamado struggle at something for the first time Akatsugi had really seen.

They'd started with fingers. It had initially taken him almost ten seconds… to grow fingers. But just having the kid focus had helped cut that time down a little (still not enough, but a little), so Akatsugi had decided to move up and the kid was now short an arm.

"Think of the limb's structure: bone, muscle, tendons, skin. Direct the flow of energy."

"I'm trying," the kid said through gritted teeth as he watched the stump where his bicep had been. Akatsugi timed it with a wind-up watch he'd gotten from Tamayo.

Once the last finger finished growing, he glanced down at the ticking hands. "Better. You're down to five seconds for the whole arm."

Kamado didn't look appeased. Actually, he looked frustrated. "That's five seconds too long. Yours takes less than a second."

The other demon shrugged. "It's better than it was. By several seconds." He frowned and looked at Kamado's bare arm as the kid checked that his hand worked, staring at it like it had betrayed him.

"I've had over two hundred years to get my technique right." Akatsugi bent down and picked up the arm they'd just cut off. Then he held it out.

The kid blinked and looked up, frowning at the appendage and then wincing and glancing at his fingers still on the ground. He still reached out and took it, then stared at it for several seconds before looking up at the older demon. "How do I… reabsorb this?"

Akatsugi sighed, then decided to show the kid. In seconds he had his knife out and then his fingers were gone and he replaced the weapon in one smooth motion (he was getting to where he really liked the idea of having a weapon after all). The kid winced and glanced away for a moment before looking back.

The former Waxing Third decided to show the kid how he regrew his limbs by slowing it down.

"First, the bone," he said, willing the off-white color to build slowly. He hadn't known the shape or color of his bones initially, but those had been controlled by his body's own memories, which should be the case with Kamado. "Then the tendons and muscles…" he continued. This stage he knew even better than the bones. He knew every one of his muscles by feel alone. "And then the skin."

His fingers were still blue, some of the few marks that had moved over from his time as Muzan's demon. He could probably change that if he wanted to. He never really did. He liked having physical evidence of his memories, but it was something he should probably remember.

"And to reabsorb…" he picked up a discarded finger and put it to his chest, willing the skin to reach forward and curl around the appendage. After a couple of seconds, it disappeared inside him. "Don't forget to break it down. The nutrients and elements will go where they need to go."

Kamado just stared at him like he'd never seen the demon in front of him before. "That was one of the most disturbing things I've ever seen."

Akatsugi couldn't help it. He threw his head back and laughed. When he saw Kamado had been serious, he laughed harder. Then he shook his head and stood, moving his foot over his other fingers and reabsorbing them that way. Kamado watched looking both sick and fascinated.

Then he held the arm up to his chest and closed his eyes. Instead of the flesh on his torso moving, it was more like the two surfaces of skin merged together. Slowly, ever so slowly, the arm disappeared back into the kid.

Once he finished, he looked down at his bare chest and grinned at Akatsugi. "I did it!"

The older demon nodded. "You did." As slow as ever, but it was a start.

"Try growing your limbs again, but go slowly this time."

Kamado frowned. "Slower?

Akatsugi nodded. "If you go slower, you can memorize how it looks and feels. That should help." Well, he thought so. Whenever Hakuji hadn't gotten something, Master Kaizo had simply slowed down and shown him every little move. He'd hated it back then… but it had worked in teaching him.

Two minutes later, Kamado was looking at the stump of his upper arm again and concentrating on regrowing the entire limb slowly and in order.

"Again," Akatsugi said as he gestured for the kid to absorb his arm back.

He had Kamado do that several more times before he encouraged the kid to grow his arm back as fast as he could.

He did it in less than two seconds. Still not the best, but now it was respectable for a Waxing Moon (former or not). And while it still took him several seconds to reabsorb any lost limbs, it no longer took minutes. Kamado hadn't even been consciously working on that part of the exercise either.

"We should call it a night," Akatsugi said finally, stretching. "We'll get back to this tomorrow.

"Okay!" the kid said with a firm nod.

"Just one more thing before you go…" the former Waxing Moon couldn't help himself. Kamado turned his attention on his 'sensei' and Akatsugi couldn't help but smile a little smugly. "This ability to reabsorb can be used to absorb other things too."

Kamado blinked. "Like what?"

Akatsugi shrugged. "Anything you want, I suppose." He paused and rubbed the back of his head as he thought about that. "Never thought about it, but you could use this technique to hide things in your body. Go figure."

"Like… weapons?" the kid tipped his head to one side. "Is that what other Waxing Moons used it for? I always wondered where Gyutaro hid his weapons."

The older demon rolled his eyes. "Like food. Do you really think Kokushibo lowers himself to actually taking a bite out of people? Oh, no. Mr-I-am-a-samurai-and-thus-above-you-all simply immobilizes his prey and then absorbs them."

The sick look had returned and Kamado had a hand over his mouth, whether to keep bile back or to just show his utter horror, Akatsugi didn't know.

"Douma can do it too," he pointed out. "Although he prefers to… 'get personal', as he says," Akatsugi shook his head in disapproval. "Not that I have any room to talk."

A contemplative silence fell over them for several seconds before Kamado steeled himself and bowed.

"Thank you for your instruction."

Akatsugi raised an eyebrow in amusement. "I cut off your limbs and made you watch me do the same, and you're thanking me for it?"

His eyes seemed to become diamonds as the older demon watched, a will of steel showing through the glowing red. "It will make me stronger and you are helping me. I will find a way to repay you."

The former Waxing Third felt himself soften and didn't even feel too disgusted at it. "Take out Muzan, and we'll call it even."

The smile the kid shot him wasn't his normal smile… or really, any smile he'd ever seen on the boy's face. It was… complicated; not cruel or smug, per se (although it would have been on Muzan, though), but it was a smile that guaranteed the owner would show no mercy. There was both kindness and hatred there, both determination and weariness as well. It was… downright terrifying on the kid.

'That,' Akatsugi thought to himself as he felt his eyes widen against his will, 'is a Waxing Moon.'

"Deal."

Then the sunshine smile returned and the boy turned to leave.

And suddenly Akatsugi realized how dangerous the boy really was, and how much he'd been holding back. For whatever reason… the former Kizuki hadn't seen his full strength. He doubted anyone really had… even the kid himself.

"Huh," he muttered to himself as he watched the demon progenitor walk away.

Then something occurred to him, and he figured he should probably say something as soon as possible. Akatsugi didn't want to give the kid the impression he'd been holding out… for more than one reason.

"Oh, kid!"

Kamado stopped and turned to look over his shoulder.

"Just realized I forgot to mention, that whole thing about 'size', 'shape' and 'function'? That all applies to you now. Learn to manipulate your flesh and you'd be surprised what you can do. Same concept as reabsorption." With that, Akatsugi held up his hand, now more of a shovel. He'd never been great at body manipulation, choosing to focus more on regrowing limbs and such by tapping into the body's instincts and memories. When changing parts of his body into other things, though, shape had always been his strength.

The kid just blinked, then looked down at his hand and back up at Akatsugi.

"Practice before tomorrow," the older demon said.

Kamado nodded firmly. "Right."

The former Kizuki was positive he'd seen a true glimpse of the real Kamado Tanjiro last night – the boy with the will and determination to do whatever he had to do to protect his family and kill the demons threatening their safety.

And he found himself honestly and truly believing that Kamado would come out on top.

That didn't mean some of what they'd have to speak about and train for today would be pleasant… for either of them. Akatsugi sighed at the prospect of everything he would have to face once he left his room… then grinned. How could he not? Even if he had to have some potentially unsettling discussions with Kamado, he was getting stronger. He was learning new things, teaching others and sparring all the time.

The next time he saw Douma – or even Kokushibo, he'd be ready.

Also, he had a new demon he wanted to fight, the Wind Pillar (former? He didn't think the man had been stripped of his title…). The guy was sleeping right now, but hoped he could meet (and fight) him soon.

xXx

"You wished to speak with me, Oyakata-sama?" Tanjiro asked as he sat down across from the Demon Slayer Corps Head. Kagaya heard more than he saw the door to the room slide closed as his daughter left. He focused as best he could on the settling blur of color in front of him.

"I did," he said, voice grim. "We received a missive from Urokodaki-san."

He didn't see the boy's face pale, but he could sense the change in his demeanor. "Is it Nezuko? Is she alright? Did she not make it back?"

Kagaya held up a hand. "She is fine. The problem is that she came across your sister on the way to Mount Sagiri."

A pause. "Hanako? Is she alright?"

"Yes. She is fatigued and likely in mourning but physically unharmed."

He heard a hitch of breath. "In… mourning?"

"She and Rengoku-san were attacked by Waxing One. He… sacrificed himself to save her."

Kagaya saw a sharp movement – Tanjiro's arm, he was sure – in an upwards direction and heard a loud gasp.

"Why?" the boy asked quietly.

Kagaya blinked. "Why what?" he prodded.

"Why did Muzan attack them? What was the point?"

"We have two theories: The first is that he wants to attack the cultivators to undermine our ability to recruit and train. The second theory is that he would like to try and get at your sister. From what we heard, the latter is a strong probability. He wants to conquer the sun, but has likely realized that recruiting you or Nezuko-san will be… difficult."

"He still thinks we can conquer the sun for him," Tanjiro whispered harshly.

Kagaya nodded. Then he coughed as politely as he could to try and alleviate some of the itchiness in his chest (it didn't work very well) before focusing back on the demon across from him.

"Nezuko-san is positive that she was able to avoid leaving a trail, but they are still planning on moving to a new Wisteria house soon. Everyone." The nearly-blind man waited for his subordinate to react to that.

"So he's taken another mountain from us…" Kamado said quietly. "Another home."

Kagaya's heart went out to the boy. It was never easy to leave behind a beloved home. "Such is his way," he said.

Tanjiro took a deep breath and then let it out. "As long as they are safe, that is all I can ask. Perhaps I should go and help them move?"

Ah, Kagaya didn't even have to bring it up himself. He'd hoped the conversation would go in this direction. "I apologize for asking this of you, but I would ask that you not. The time for the attack on the Swordsmith Village that you remember from some of your previous timelines is coming up. I already have Himejima-san stationed there and am planning on sending Kanroji-san once she is finished with her current mission, and I would like you there as well, just in case.

"Also, it should make for ideal training with Himejima-san."

Once again, he waited patiently for an answer, watching the black and green blur across from him as Tanjiro shifted.

"I… suppose, if my family is alright…"

"Urokodaki-san insists that they are."

"I… do need to train."

Kagaya nodded. "My thoughts exactly. Your training is important and I would prefer to see it completed as soon as possible."

This time, the silence that fell weighed on the conversation.

"You expect an attack soon."

"I do. Almost all reports of demons – besides the attack on Rengoku-san and your little sister – have stopped. I fear this is the calm before the storm. I've sent Kanroji-san and Iguro-san on missions to double check some things, but I do not expect they will run into problems… yet."

The blob moved in what Kagaya supposed was a nod. "The same thing happened about four months before Muzan's final attack the first time."

"Indeed. Although we have changed so much we cannot count on that. He could attack tomorrow, or in a year."

Tanjiro sighed. "Yes, I know."

"I am asking you to be at the head of the charge to destroy him."

This time, the blob moved down… in a slump? The Corps Head didn't know. But then he straightened and his voice spoke with confidence. "I had already planned on it."

Kagaya nodded and smiled, albeit wanly. "I assumed so, but I still wanted to speak with you about it so we can coordinate."

He thought Tanjiro relaxed a little. "Yeah."

"Then I will ask you to leave for the Swordsmith Village tomorrow."

"What about Sanemi and Kimiko?"

"They can stay here or go with you if you would like. Normally you would be taken via a piggyback route with various Kakushi to maintain secrecy, but I do see little point in keeping up with that protocol when the Village is likely already compromised," he paused and let himself smile apologetically, "and Kakushi would find it difficult to carry demons the entire way, and thus you can take whoever you wish. I trust you."

"Oh. I'll… um, ask them, then."

Another pause, and then the boy spoke a little sheepishly. "What about Genya-san?"

Kagaya could practically hear the wince in the other's voice.

"Ah, yes. He is there. I am ordering you to stay away from him except under the most dire of circumstances or if Himejima-san says otherwise."

"Oh… uh. Hai, Oyakata-sama." Poor child. He sounded so disappointed.

After a couple more seconds of quiet, during which time Tanjiro seemed to want to get his thoughts together, Kagaya decided to give him a little nudge.

"Why don't you go speak with Shinazugawa-san so we can continue to make plans."

Tanjiro seemed to snap out of whatever reverie had overtaken him. "Hai, Oyakata-sama!" he said as he stood and bowed. "I will return shortly."

And with that, he left.

Kagaya smiled. They were truly lucky to have Kamado Tanjiro on their side.

xXx

AN: I'd like to thank TimeLordTim, Kaylessa, Found and Quathis for their help on this. Thank you guys so much! Also my discord community for helping me figure some things out for this chapter. Luv you guys!

Discord: discord. gg/xDDz3gqWfy (no spaces)