After saving everyone on the train and almost losing their dear friend Rengoku, Lynn and her friends all returned back to the Butterfly Mansion to tend to their wounds and begin their recovery to full health. Though, Lynn was a special case because of the recent change in her body due to her exposure and usage of the Tenseiga. When examined by Shionbu, the Insect Hashira was surprised when the wounds described to her by Lynn were suddenly gone with little to no traces of any injury left. Shinobu also examined closely the bodily changes that happened to her, like her sharpened nails and the white streak that ran through her hair. Without any real reason to put her for bedrest, Shinobu decided letting her train and get use to her newly strengthened body would be best. Lynn was sat on top of the roof of the nursery with the Tenseiga unsheathed as she stared at herself in the reflection.

"This is where we part ways, Lynn. I will continue this path on my own, as I intended from the very beginning. Farewell." Those words echoed through her mind as she remembered you leaving her.

"I'm a...half-demon..." Lynn muttered as she could only remember how the two of you parted ways after the train incident. "It won't be the last time we meet right? Lord Y/N...?" Her heart ached a bit as she couldn't bear the thought of never seeing you again.

"Young Lynn!" The girl's thoughts were suddenly interrupted from the sound of someone's voice as she turned to see Rengoku down below.

"Ah, Rengoku." Lynn was surprised to see the Flame Hashira as she put the Tenseiga away and stood back up. "Ha-Eh...?" Lynn jumped off the roof, but with her newly found strength, jumped too high and far as she began to fall towards the bushes near the perimeter of the house. "Uwaaaaah!!!" She screamed as she crashed into the bushes and Rengoku watched it all with a smile on his face.

"Humu! You seem like your back at full strength already. Actually, you look stronger than before."  Rengoku laughed as Lynn crawled out the bush with a few leaves and twigs in her hair.

"Blegh..." Lynn spat out a leaf from her mouth before looking up to Rengoku from the ground. "Are you leaving already, Rengoku?" Lynn asked.

"Yes. After being revived, I found my wounds already beginning to heal. There's still some serious pain and my breathing hasn't fully recovered, so I won't be taking missions for some time. Though, there's plenty of things a slayer can do when not on mission, so I'll be tending to those." Rengoku said as he noticed a strange and uneasy look on her face. "What's wrong?" He asked.

"I...I'm not sure how to approach this situation that I'm in..." Lynn said as Rengoku more or less understood what she was talking about.

"About being a half-demon?" Rengoku said as she averted her gaze even more.

"I'm a Demon Slayer. I'm supposed to hunt demons. That was my duty, but..." Lynn looked down and examined her sharpened finger nail claws. "...Now, I'm a half-demon...I don't know if I'll ever be human again." She said with a hint of worry and sadness.

"But you're still human at heart." Rengoku said as she looked up to see him smiling. "Even if you've turned part demon, you still have a human heart and human emotions. This power you have shouldn't be looked at as a curse. You should look at it as you becoming even stronger, to protect the innocent from the demons who prey on them. Hold your head high, Young Lynn. You'll accomplish great feats in the future, I'm certain of it." Rengoku said while patting her on the head as she couldn't help but smile a little from his warm and kind words.

"Thank you, Rengoku..." Lynn appreciated his words to her as he pulled his hand away.

"Don't worry about it. If you ever need some help, don't be afraid to turn to me or any of us Hashira." Rengoku said before turning away and taking a few steps towards the exit. "Now then, I'm off  to fetch some records for Tanjirou. I should be back before dusk." He said as Lynn turned towards him and leaned forward to bow to him in respects.

"Take care, Rengoku." Lynn saw him off as Rengoku just smiled and waved at her before heading out the door of the perimeter.

After seeing Rengoku off, Lynn wandered around the butterfly mansion wondering what she should do. All her wounds had healed but there was no one to train with since Tanjirou, Zenitsu, and Inosuke were still recovering. Eventually, she wandered out of the Butterfly mansion and into the grassy plains where she remembered you and your father once dueled. The cracks in the earth and craters from yours and your father's attacks remained as she stared at them before staring down at her hands.

"Dragon Strike." Lynn remembered the attack you unleashed before as she began to ponder her thoughts.

"I wonder..." Lynn muttered to herself before she finally caved into her desire to test her newly acquired strength.

Running back to the Butterfly mansion, Lynn leaped into the air and onto the walls of the perimeter before jumping down and running to the patient's rooms. Sliding the window open, she hopped onto the window cill and scared Zenitsu who was peacefully resting in bed eating onigiri's.

"AHHHHHHH!!! WHAT WAS THAT?!?" Zenitsu screamed as he turned around to see Lynn staring at him strangely from the window. "YOU! DON'T JUST GO AROUND JUMPING INTO WINDOWS! THAT'S A CRIME, YOU KNOW?!" Zenitsu yelled at her as Lynn just entered the room before walking over to her bed. "HEY, ARE YOU LISTENING?!" Zenitsu yelled as Lynn's eyes turned red.

"WILL YOU SHUT UP ALREADY?!" Lynn roared at him in annoyance as Zenitsu had fallen silent as he froze in fear of Lynn's sudden snap. "Jeez!" She huffed as she turned around and walked towards her bed. 

"Is something wrong, Lynn?" Lynn heard Tanjirou as she walked passed his bed and went over to hers before reaching underneath.

"No, just wanted to try something that came to mind." Lynn said as she grabbed her sword and Tenseiga out from under her bed before standing up and walking over to the window next to Tanjirou. "How are your wounds?" Lynn asked while climbing into the window sill.

"They're more or less fully healed. They're still very sore, but I think I can begin training soon." Tanjirou said while holding the side where he was stabbed during the train mission.

"I see. I'll be waiting to train with you guys soon." Lynn said as she gave him a quick smile before leaping out of the window.

After retrieving her blades from her bed and heading back out of the Butterfly mansion, Lynn ran back into the battle scarred field where she took a firm stance and drew her Nichirin blade from her side. Feeling a bit optimistic, Lynn closed her eyes and began to try and channel her inner strength into her blade. She imagined the energy inside of her as a swirling blue collection of demonic energy and tried to make her body extend its energy into the blade. In her mind, she envisioned your Dragon Strike technique and subconsciously slid her left leg back as she held her blade across her chest with the point of her sword on her left side. Feeling that she had channeled all the energy she could in her body, Lynn's eyes shot open as began to move her blade in a horizontal slash.

"HAAAAAHH!!! DRAGON STRIKE!!!!" Lynn yelled at the top of her lungs as she cut the air in front of her.

The sound of the air being sliced was all that could be heard before silence filled the field again while Lynn stood there awkwardly after nothing came out from her attack. A red hue crept all the way up to her ears as she dropped her blade and covered her face and crouched down in embarrassment. 

"AHHHHHH!!! WHAT AM I DOING!? THAT WAS A TOTAL FAILURE!! I'M AN IDIOT!!!! IDIOT!!!" Lynn cried out in an extremely flustered state while shaking her head back and forth. 

While scolding herself for trying to attempt something beyond her capabilities, she grass around her blade began to suddenly wither and die. Hearing the strange sound and seeing a dark spot spread across the grass, Lynn lifted her head in confusion to see a green hue running across the sharpened side of her blade as it pulsed brightly over and over. She stared at it in awe as she reached over and grabbed the blade by its hilt, picking it up and staring at it in wonder. Lynn was beyond shocked to see what she concluded was her demonic energy had actually manifested and extended out to her weapon. Taking a firm stance once again, she held the blade with two hands with the steel pointed behind her on her rights side. Bring her back right leg forward, she lifted the blade above her head and yelled from her gut as she slashed the air in a diagonal direction from the right and a barrage of strange green lights shot out from the glowing part of her blade. Lynn gasped in shock when the barrage attack she unleashed reached the tree line of the nearby forest, slicing through the trees and cut four of them down. Slowly, a smile crept onto her face before she curled down a bit before leaping into the air.

"YAHOO!!!!!" Lynn exclaimed with great joy as she giggled in excitement of her new found ability. "With this, I'm sure to be able to take down Muzan and any demon that stands in my way! I can--Huh?" Lynn suddenly felt dizzy as she fell to one knee and stabbed the blade into the ground to support herself. "I-Is this some kind of draw back from using that technique...?" Lynn wondered while staring at her blade as steam came off the glowing edge.

"So this is the extent of your new abilities, then." Lynn heard a voice speak from behind her as she was shocked by the voice.

"KYAAA! Who is that!?" Lynn leaped away from the person behind her and turned around to see who it was, only to be even more shocked by who was standing in front of her. "L-L-LORD SESSHOMARU!" Lynn immediately prostrated herself before your father and bowed her head.

"Well, one can only expect such a feeble attack as that for a newly born half-demon." Sesshomaru said as he looked down at Lynn. "However, this is the outcome of demonic energy being flowed through a blade made by humans." He said as Lynn was confused by this statement and stared at her sword, only to gasp in shock when the blade suddenly melted and only an empty and partially melted hilt remained. "Demon of half-demon, your demonic energy will not work with weapons made by humans." Sesshomaru said as he turned around and walked away.

"W-Wait, my Lord!" Lynn called out as Sesshomaru stopped and turned his head back to glance at her. "Why did you come? Were you hoping to find Lord Y/N?" Lynn asked as he just turned away from her.

"Tenseiga resonated with my Bakusaiga. I came only to figure out why the Tenseiga called to my blade, which apparently was to show me what you had become." Sesshomaru said as Lynn felt a bit disheartened hearing that was the only reason for him being there. "Continue to push yourself beyond your limits. Even you can become stronger than before." Sesshomaru finished as this surprised Lynn and she looked up to see him fly away.

"T-Thank you for your words of encouragement, Lord Sesshomaru! I am forever grateful!" Lynn yelled at the top of her lungs as she watched him disappear into the clouds above. "But..." Lynn's face turned back into a look of concern as she stared at her melted blade on the ground. "...How am I supposed to get stronger with these new abilities, when my demonic energy is just going to destroy my human weapons?" Lynn wondered as she was left to ponder for herself how to become stronger.

After deciding to take the rest of the day to recover her strength, Lynn was having dinner with everyone in the dining room as Aoi and her three helpers continued to serve them food. Lynn was sat at the left end of the table and took bits of rice from her bowl as she felt a strange staring sensation coming from her left. Glancing over, she noticed Naho staring at her with a gaze of wonder and stars in her eyes as Lynn felt a bit flustered by the intense staring. The half-demon girl put down her bowl of rice and turned slightly to face Naho as the young girl squeak in embarrassment of being caught staring.

"Is something wrong, Naho?" Lynn asked as the little girl waved her arms side to side.

"N-No! I just think you look really pretty with the white in your hair..." Naho admitted in an embarrassed tone as Lynn stared up to try and look at the white streak in her hair, but giggled at her compliment.

"Thank you, Naho. Your braided twintails are really cute." Lynn said while patting Naho on the head.

Just then, the dining house suddenly began to rattle and shake, startling everyone inside. Lynn stood up with concern only to grab onto Naho who clung to her side when the dining house shook violently for a brief moment. Tanjirou and Inosuke both stood up hastily while Zenitsu screeched in fear and hid under the table, and as the looked around trying to figure out what was going on, the shaking slowly stopped and there was a strange noise that came from outside. It sounded like an animal making a noise that none of them had heard before, and as Tanjirou and Lynn glanced at each other, Tanjirou gave Lynn a nod as she understood and rushed off outside as she was the only one currently strong enough to handle any sort of engagement. Running through the hall and heading out the open doors on the side, Lynn leaped onto the roof and turned towards the strange noises to grow a surprised look on her face when she saw what was making those animalistic noises. Out in the garden, there was a two headed brown dragon with a muzzle for each head and a saddle for someone to ride on. The two headed dragon spotted her as both heads turned and let out light mewls or sorts as it turned towards her.

"W-What is that? A dragon? Why does it have two heads?" Lynn questioned the reason for this beast to suddenly appear, before growing a confused look when she saw something strapped to the saddle. "What is that?" Lynn wondered before jumping a bit when the dragon mewled once more at her and took a step forward towards her. "Does it want me to come to it?" Lynn thought as she slid down the roof and jumped down to the ground.

"Lynn!" The half-demon girl heard someone call her and turned to see Shinobu running towards her with her blade drawn as Kanae followed behind her, and Tanjirou and the others ran behind them. "Step aside! You don't have your sword!" Shinobu ordered as Lynn put her hands up and stood between them and the dragon.

"Wait! I don't think it means any harm!" Lynn said as the Hashira and her Tsuguko stopped in their tracks. "It's calling to me." Lynn said as she turned back around to the dragon as it patiently waited in its place. "Do you belong to Lord Sesshomaru?" Lynn asked while taking a step forward.

A-Un simply lowered their heads and sat down gently in the garden as the left head turned to its back to gesture to the item attached to the saddle. Lynn let out a quick sigh of relief when she was able to confirm that the dragon did indeed come from your father and walked over to its side. Zenitsu shivered in fear of the sight of A-Un, while the others watched closely to see what was going to happen next. When Lynn came to his side, she was surprised when she found a weapon attached to the saddle.

"This is...Naginata?" Lynn wondered as she stared at the weapon in awe and her hands hovered over it.

"What is it, Lynn?" Shinobu asked as she carefully came around the side and stood behind Lynn.

"I think it's a gift from Lord Sesshomaru..." Lynn said as she carefully took it off of A-Un's saddle and examined it closely.

"Lord Sesshomaru?" Shinobu asked in confusion of who that was.

"Lord Y/N's father." The two girls turned to see Tanjirou walk over near A-Un. "Maybe he gave this to you so that you could use it against demons." Tanjirou posed the assumption as Shinobu was confused. 

"Who is Sesshomaru?" Shinobu asked Tanjirou.

"He's the Supreme Conqueror of all Demons. He came to see Lynn when she was alone. At least, that's what she told us during dinner." Tanjirou said as the right head of the dragon, 'A' ,turned and came closer to Tanjirou. "Ahhh! N-Nice dragon!" Tanjirou said while keeping his distance and 'A' let out a gentle bellow.

"There's a note attached to the hilt under the blade." Shinobu pointed out as Lynn looked to see the note tied by a string and removed it from the weapon to read it aloud.

Play Song At Top
Title: Unbreakable Heart (Yashahime Ost)
Link: 

"This is Yukari no Tachikiri, it should aid you in your training. This is a weapon forged by demon who has made weapons for centuries, so it will be able to handle your demonic energy as you use it. This is more than enough for you to kill that vermin whom my son hunts down. We will most certainly not meet again, but A-Un will check on your from time to time. That is all." Lynn read the note aloud as she couldn't help but smile as she stared at the dragon with gentle eyes. "So your name is A-Un, huh? It's nice to meet you, A-Un! Ah! Let me guess! The right head is 'A'' and you over here on the left is 'Un' right?" Lynn said while placing a hand onto A-Un's body gently, and the dragon could not help but see Rin in both their eyes as A-Un bellowed gently and both heads turned to get closer to her. "There, there..." She placed the Naginata gently to stand against A-Un's body as she rubbed both of his heads under the muzzles as both heads closed their eyes in pleasure. "Make sure to let Lord Sesshomaru know how grateful I am. And thank you for coming all this way to give me this gift. I'll make sure to use it properly." Lynn thanked the dragon as it stood back up and Lynn grabbed her new weapon and stood to the side.

"Then, this two headed dragon is a demon also? Goodness, you are making quite special friends each and every day aren't you, Lynn?" Shinobu said with a giggle as Lynn watched A-Un take to the skies.

"I'll see you soon, A-Un!" Lynn waved goodbye as A-Un flew off into the night sky and she stared deeply at her new weapon. 

"Usually, you have to be very skilled and a request must be put through to have a special weapon in the Demon Slayer Corps." Shinobu commented on the specifications on the weapons the Demon Slayers were to use in combat.

"Ah! W-Well, it's not like I'm saying that the Nichirin swords aren't good enough or anything! They're perfect weapons! It's just that for my specific situation, I think that this is an exception?" Lynn tried to come up with an excuse to use the weapon given to her, but Shinobu wore a calm smile on her face.

"Don't worry. This is a necessity for your power and ability to fight demons. I believe you'll truly become stronger in no time. Just make sure to take breaks every now and then, okay?" Shinobu said in a supportive tone as Lynn smiled.

"Yes, ma'am!" Lynn said as she leaped into the air and landed on top of the dining room roof as she twirled around the polearm before gripping it firmly in both hands and focusing her demonic energy into the blade. "Yukari no Tachikiri..." She only thought of her weapon and soon it began to rattle in her arms as a green glow began to emit around the blade as her eyes shot open. "HAAAAAAHH!!!!!!!" In one swipe through the air, Lynn unleashed the attack she had discovered before and a barrage of green demonic energy shaped like swallows were unleashed from her blade and flew into the night sky. 

"A-Amazing..." Tanjirou muttered as everyone stared at her with amazement as Lynn huffed breaths with an excited smile on her face. 

"I don't feel as tired as before...and it was easier to control my demonic energy..." Lynn thought as she stared down at the polearm in her hands. "New possibilities have just been opened to me, and it's all thanks to them my Lords..." She thought as she stared up at the moon with pride as the image of you and Sesshomaru pondered in her thoughts. "I will become stronger...and be someone they can look at with pride. Kibutsuji Muzan...your time is coming soon..." She thought with a smirk on her face as she was ready to master her new abilities and become as strong as she could ever be to protect the innocent lives who are ravaged by the hands of merciless demons.