Another long chapter... and the end is very close. Are you ready for the trip to the destination, whatever it will be?

Twenty-three years ago…

In the middle of the night, Noelle woke up with a gasp, her green eyes open wide. Her breath uneven and her body shaking, the three years old girl started to cry. She cried for a little while, until the door of her bedroom opened and the light got turned on.
"Noelle? What happened? Did you have a nightmare?"
It was her mother, who came check on her after hearing her crying from the neighboring bedroom. Frisk walked up to her daughter and sat down on the bed, right next to her. Noelle immediately wrapped her arms around her mother, burrying her face into the soft blue dressing gown. She kept crying, while Frisk gently rubbed her back to soothe her. After a moment, Noelle managed to speak through her sobs.
"Mommy… It was bad dream… I was lost in place I don't know… and many people around I don't know… a-and you not here… You and Dad not here… I was alone…"
"It's okay, Noelle. It's okay, it was just a dream…" - Frisk said to her daughter softly, while stroking her brown hair - "I'm here, with you."
"I'm afraid… What if you leave?" - Noelle asked with tears.
"I'll never think of leaving you." - Frisk said, sounding determined - "Dad and I love you very much, Noelle. No matter what happens, you're not alone."
Noelle tightened her embrace around her mother, as if in fearing that she might vanish at any moment. Frisk returned the embrace, understanding her child's insecurity. She then started to hum a tune, to help Noelle relax. As the tight grip on her dressing gown loosened a little bit, Frisk sang a calm and slow song.

When the light is running low
And the shadows keep to grow
And the places that you know seem like fantasy
There's a light inside your soul
That's still shining in the cold
With the truth, the promise in our hearts
Don't forget
I'm with you in the dark.

Noelle seemed to have calmed down, so Frisk gently laid her back on the bed, covering her with the blanket. As Noelle was looking at her mother with sleepy eyes, Frisk promised with a gentle tone:
"I promise that I'll always be with you. Even if we're far apart, my heart will be with you. You're very loved Noelle, and you're never alone. Please, never forget this."

Present day

"Chara wants to… 'snuff out my light'? Is that what she said?" - Noelle asked with a shocked, yet pensive expression.
"Yes, those are her exact words." - Sam confirmed - "She wants you dead, or corrupted, as her revenge on our family."
After Chara attempted to kill the twins and Gaster recovered his memory, the others had been informed. Sans, Papyrus and Frisk were the first to know, and Sans got lectured for a while by the couple for leaving Sam and Piper wander by themselves. Noelle found out about it all later, when she returned home after her training with Undyne. She was obviously shocked and angry that Chara tried to kill her children. Chara went way too far this time, and time came for her evil deeds to stop. But how could Noelle stop her without reaching the exact result Chara expected?
"What should I do..? Is there even a way to convince Chara to give up on vengeance? Or is bloodshed really unavoidable..?" - Noelle asked somewhat anxiously - "No... it can't be so, right..? I don't want to believe it."
"Then don't." - Gaster said , making everyone look at him - "If there's anything that I learned from you and your parents is that there's always another way. You don't have to kill and if you don't, paying with your life isn't always needed. It must be strange to hear those words come from my mouth…"
"it is indeed." - Sans confirmed.
"NO, NOT REALLY." - Papyrus contradicted his brother, shaking his head - "IT'S STRANGE, BUT IN A VERY GOOD WAY!"
Gaster couldn't suppress a light chuckle at Papyrus' words. Noelle looked at him with a look of someone who needed an advice or some encouragement. So she asked Gaster:
"So, you think I can find another way?"
"You helped me find my way of redemption. There's still a way to go, but I wouldn't have made the progress without you. You also forgave and helped Asriel, without sacrificing either your lives." - Gaster answered, then his eyesockets glowed yellow briefly - "So I know you'll find a solution to this puzzle."
Noelle was affected by Gaster's words and faith in her, so she couldn't help but blush a little.
"Gaster's right." - Frisk joined in - "You are a strong person, Noelle. And you have all our trust and support to guide you in the dark hours."
"Yes, we all believe in you." - Piper added - "You are the Savior, you can do anything!"
"YOU SAID IT, PIPER." - Papyrus agreed with the girl - "I SAID IT BEFORE AND I'LL SAY IT AGAIN: YOU ARE VERY GREAT, NOELLE."
"so yeah, keep your chin up. doubting's my job." - Sans said, winking.
"Thank you, guys…" - Noelle lowered her gaze - "Your words mean the world to me."
"But what? What's bothering you? Well, besides the obvious…" - Frisk asked her gently.
"It's nothing, I'm fine. I just feel a bit unprepared to face Chara." - Noelle said, before standing up from the couch - "And I'm tired. Fencing lessons with Undyne exhausted me. I shall sleep earlier today."
Frisk's concern didn't vanish though. She knew better than assume that her daughter was as "fine" as she claimed. Nobody baught her saying actually. But none of them dared to press further on the matter. They all knew that Noelle couldn't deal well with her worries when pressured. But Frisk also knew that after letting her breathe for a little while, Noelle'd always be more open to talk. And so, she would go talk with her later.
"Have a good night, everyone." - Noelle then turned to Gaster and said with a light smile - "It's nice to see you back among us, Gaster."
"I'm glad about it too." - Gaster replied, the look in his eyes soft.
Noelle then affectionately ruffled her kids hair, before going upstairs and then to the bathroom. A few moments later, the family heard a faint noise of water running, which meant that Noelle was about to take a bath and wouldn't come out for a while.
"POOR GIRL… NOELLE REALLY IS STRESSED BECAUSE OF CHARA AND HER DEEDS." - Papyrus commented sadly - "I WISH I COULD EASE HER BURDEN SOMEHOW."
Sam and Piper exchanged a serious but sad look and sighed.
"It's all our fault..." - Sam said.
"What? How would that be your fault, Sam?" - Gaster asked.
"Piper and I brought her to Undertown in the first place." - Sam replied - "If we didn't, she wouldn't be the Savior now."
"If we didn't show up at her door, she would've lived a normal and… long life." - Piper added with sadness - "We've been so selfish."
"We never regretted searching for her, but now… I think that maybe we should've left her be." - Sam said, self-directed anger written on his face - "Just because our life back then wasn't enough for us. If only we were just satisfied by what we already had…"
"Sam, Piper, stop that." - Gaster said, making the twins look up at him - "What's happening now isn't your fault in any way. And I can understand that our life didn't satisfy you… I wasn't the best back then."
"only 'back then'?" - Sans asked sarcastically.
Frisk and Papyrus gave him a look, the moment not being appropriate for his sarcasm. Gaster simply ignored Sans' words and pursued:
"But don't berate yourselves. You did what was right. It was thanks to you that everyone was saved. You might've had some personal interest in finding your mother, but you did the right thing."
"Besides, you made Noelle much happier when you brought her in the town." - Frisk added with a reassuring smile - "Noelle's life sure was calmer, but it wasn't really a happy one."
"IF ANYTHING, NOELLE IS VERY GRATEFUL TO YOU FOR FINDING HER." - Papyrus said on his turn.
"You... you think so?" - Piper asked.
"I AM SURE OF THAT!" - Papyrus answered with confidence - "I KNOW MY DAUGHTER WELL, SO TRUST ME WHEN I SAY SHE'S HAPPY ABOUT HOW HER LIFE TURNED."
"But now she might die, and she had so many problems after we found her…" - Sam stated, looking still guilty.
"Hardships are just a part of life. But those are what make all the good moments very special." - Frisk explained gently.
"It took me a lifetime to understand this, but I agree with Frisk." - Gaster said, making Frisk look at him with a surprised look - "So, please don't think what's happening now is your fault."
The twins nodded slowly after a moment. They understood that they weren't the ones to blame for every problem Noelle got to solve, but it didn't make them feel better that much. No matter whose fault it was, it barely changed anything about Noelle's fate. Gaster then suggested the twins to go back home, since it was getting late. After Sam and Piper wished goodnight to their grandparents and Sans, they went out of the house along with Gaster. As they were walking back to their house, Gaster was deep in thought. When they finally returned home, and when the kids were ready to go to bed, Gaster took a moment to sit down on Sam's bed and said:
"Don't blame yourself for what's actually my fault."
Sam and Piper looked at their father curiously, not catching what he meant at first.
"I was the one to de-code our world. It's because of me that Noelle got separated from her parents. Not only that, but I also weakened the space-time fabric, which permitted Chara to cross timelines."
"W-what?" - Sam asked with rounded in surprise eyes.
"Yes. Before she knocked me out, Chara told me that it was thanks to my work that she could arrive. Otherwise, she wouldn't have moved from her timeline." - Gaster explained - "This is why she tried to kill me, actually. She feared that I would find some way to send her back."
"That's awful…" - Piper muttered.
"I know, some of my mistakes did damage beyond repair."
"No, I meant it's awful what Chara did to you. She's just horrible."
"And again, you choose to think about my wellbeing rather than my mistakes…" - Gaster said with a sad chuckle - "But the reason I'm telling you this now is that you two are much better people than I am. This is why I don't want you to feel guilty for my sins."
"Oh, but you are a good person too now." - Sam said genuinely.
"And it was Chara's choice to come here." - Piper added.
"Maybe… I just want you to always be as good as you are today." - Gaster said to his children softly.
The kids nodded, as though wordlessly promising that they would. Gaster then knelt down to plant a kiss on Sam's forehead, then walked up to Piper and did the same. Before going out of their room, he said:
"Goodnight Sam, Piper."
When the twins wished him to sleep well in return, Gaster closed the door and walked long the corridor to his own bedroom. After he got himself changed, he laid down on his bed and stared at the ceiling for a long while. The memories of his time at the hospital were tormenting him. Gaster just started to move on from his past mistakes… and now he had new ones weighing on his shoulders. Just why was his life made like this? Was he doomed to live with only more regrets? It would take Gaster some time to forgive himself for how he behaved around Sam and Piper during his amnesia. But the twins already forgave him, which was a treat to his soulache. As Gaster kept staring at the ceiling, he suddenly remembered what Noelle once told him. She told him that out of the bad things done, some good things could come out of it. And so, miraculously the weight on Gaster's SOUL lighten. The amnesia was actually a trial for the love between Gaster and the twins. A trial that they overcame. The thought of it made the skeleton smile. Feeling more relaxed, he finally closed his eyes. Besides, he realized, his time at the hospital wasn't exactly a bad one. "I wonder if Patty's sleeping well now…" - Gaster wondered, before he dozed off.

Meantime at Noelle's house, the young woman was sitting on her bed, listening to the music emitted from a music box she had received on her birthday. Noelle remembered her own surprise when she heard it for the first time, because the music sounded familiar. Frisk explained her that it was because that was a song she used to sing to soothe Noelle when she was still a little kid. And so, Noelle would listen to the music at dark hours. It was a moment just like that now. Noelle sighed sadly, as she stared at the music box in her hands.
"I wish I was a kid again." - Noelle commented to herself - "Back then, a song was enough to lift my spirits."
"Maybe a chamomile will help?" - Frisk said from the doorframe.
Noelle gasped, startled by her mother's sudden presence, then closed the music box and put it aside with a sigh. Frisk walked up to her daughter and handed her the cup of tea.
"Drink. You need to relax if you want to fall asleep."
"Thank you, Mom." - Noelle said, then took a sip with a content sigh - "You know what I need and when."
"That's right. Just like I know that something's bothering you right now." - Frisk stated - "And I think you should share it."
"You already know what's bothering me... Chara wants to kill me."
"Yes, but I have a feeling there's something else."
"Well, truth to be told... there is. How do you even sense those things?" - Noelle asked her mother, who just shrugged casually - "It's just that… I'm often being told that I'm the Savior. But I still didn't quite figure out what it means. What makes me a Savior exactly?"
"A savior is by definition someone who saves people." - Frisk said half-jokingly.
"I know what the word means..! But I just don't get how and why I am the Savior."
Noelle then drank a few more sips of chamomile, before pursuing to express her thoughts.
"I saved our entire world from a fake life, and then? I barely was a help to anyone afterwards. I almost lost you to Flowey, it occured to me quite late that you've been switched by Chara, I insulted Gaster while I promised to help him, and my children get in trouble because I'm bad at watching them!"
"Everyone has bad days, even the greatest heroes." - Frisk said, lying her hand over Noelle's shoulder - "There's no such thing as a perfect Savior, and honestly nobody requires you to be one."
"Then what's my role exactly? If I became a Savior, it was merely because the Dog sent me away before the De-Code could reach me." - Noelle replied, sounding almost frustrated.
"It's not just that. If you're called 'Savior', it's because you have a unique, and very powerful, SOUL."
"It doesn't change anything. My SOUL is something I was just born with. I didn't become a Savior by choice, the white dog labelled me that way." - Noelle shook her head sadly - "I am something that I never chose to be. They say we build our own fate, that everything depends on our choices. Then why was I deprived from mine? Why couldn't I decide to be someone normal?"
"Noelle, it's not because you were born the way you are that you can't make any choices. You still have the power over your fate." - Frisk said seriously.
"Do I really?"
"Do you think your father chose to be born as a test subject and then treated like one? He didn't. And yet, that didn't stop him to keep making choices, no matter how small those could seem. Papyrus made the choice to keep believing in Gaster, despite everything he's done to him. Despite what he had to go through in the lab, he decided to stay faithful to himself and always be good. If your father could make choices despite the circumstances, so can you."
Noelle thought about it for a moment and she realized that Frisk was right. Only two days ago, Noelle almost killed Chara. She could have, but she chose not to. The same could be said about the instance with Flowey months ago. It were her choices that made the timeline move in one or another direction.
"...I suppose you have a point."
"But did you try to ask the Dog about this?" - Frisk asked.
"I did... And he said that it's something I must figure out by myself." - Noelle answered.
"Hmm, then it really is something only you can find the answer to. I'm sure it's not impossible to figure out. But this only proves that you still have your power of choice. You were born with a unique SOUL, but it certainly isn't the only thing that makes you the Savior, Noelle."
"Thank you, Mom." - Noelle breathed out, before hugging Frisk tightly - "You have no idea how much I needed to hear this..."
"Please, tell us whenever something's bothering you. Keeping it all in does you no good." - Frisk advised as she returned the hug.
"I know, I'm sorry... It's just that I've been all alone for so long, so I'm still getting used to the fact there are people who'd listen."
The two women sat there like this for a few more seconds before pulling away. Frisk then took the empty cup before walking back to the door. But before she left, she turned around and said:
"Sleep well, Noelle. Your mind definitely needs some rest."
"You're right... Goodnight Mom."
"And I promise we'll figure something out regarding Chara."
Noelle nodded, after what Frisk closed the bedroom door. Noelle then smiled at what her mother just said. Because she said "we will figure something out". This reminded her once more that she was no longer alone.

Twenty-two years ago…

It was a late evening, and the entire orphanage was getting ready for bed. Noelle was already wearing her PJs and sitting on her bed. It's been almost a year now that she was found alone near a gas station and placed in the orphanage. Noelle missed her parents a lot, despite that the memories of them were getting a bit blurred as time passed. But she had faith, she believed with her whole being that her parents would return for her and take her back home. Not a day passed without expecting for them to come. As she was thinking about them again, Noelle closed her eyes and started to hum a tune she still knew by heart. A small smile appeared on her lips; humming the melody made her feel like her mom was just there, singing for her. But that little moment of peace and joy didn't last, because Noelle heard her roommate say:
"Can you stop that already? You sing almost every night, it's quite annoying. Don't you have enough of this?"
"But it's Mommy's song." - Noelle replied - "I sing to remember her."
The nine years old girl let out a tired sigh, running her hand through her curly dark hair. She then looked at the innocent toddler and spoke her mind.
"You gotta stop that. Stop waiting for your parents at the window all day. Stop singing your mother's song at nights. Forget your parents, they're not coming."
"But... but I know they'll come…" - Noelle protested quietly.
"Just accept that you're a lonely orphan, and you won't miss your parents that much." - her roomie said with an annoyed groan, then went under her blanket - "Can you just let me sleep tonight?"
Noelle sighed sadly, not liking her roommate's remark. It didn't take long for the latter to fall asleep. Noelle then pulled from under her pillow a drawing she made a couple of months ago. The picture represented herself and her parents. She was holding their hands and the three were smiling. Noelle smiled when she looked at that drawing. Because it permitted her to not forget her parents. Noelle drew them at a moment when her memories were clearer than they were becoming. Her mother was wearing a blue shirt with pink stripes and had short brown hair, and her father was wearing red scarf, gloves and boots. It was enough for Noelle to somewhat remember them. Each time she looked at the picture, she had a feeling like her parents were right there with her. As though they never left. She would always feel a pleasant warmth inside her heart. It was with a big smile full of hope that Noelle slid the drawing back under her pillow. She then closed her eyes and fell asleep. And the next day, she would keep believing.

Present day

Noelle woke up in the middle of the night with a loud gasp. She just had that same vision again, about her and Chara. About their final battle. This sent a shiver down Noelle's spine. After a moment of trying to fall asleep again, Noelle heard a noise. Something was knocking at her window with an irregular rythm. It was as if someone was throwing small stones to get her attention. With a frown, Noelle stood up from her bed and walked up to her window. As she drew the curtains, she almost screamed at what she saw. Chara was standing in the garden, her red eyes locked on her window. When the two women's gazes met, Chara grinned evilly and satisfyingly. Noelle wasn't frozen out of fear for very long. In a moment, she rushed out of her bedroom and down the stairs to the first floor. Noelle went straight to the kitchen, where there was a back door that led to the garden. But when she turned the light on and looked through the window, Chara was nowhere to be seen. Suspicious, Noelle opened the back door to peek outside. Chara wasn't there. However, there was a note stick on the door. Noelle took the paper in her hand and read the message.

I think that's enough playing cat and mouse. Let's get to serious business. Meet me tomorrow at the sunset beneath Mount Ebott and we shall put an end to our conflict once for all. You can call this a final battle of a sort. I highly advise you to be a good girl and come alone. Do as I say, and I promise no harm will be done to any of your family members once it's over. If you dare to disobey, know that you are not above the consequences.

Noelle's hands trembled, then she crumpled the note and threw it in the trash can. So this was it? The final hour almost came. Noelle really wanted to tell her parents about it. She wanted to share her fear and express all the feelings she had for them. But… the note was clear on the matter. If she involved her family, they would insist on coming with her. True, Chara wasn't a person whose word could be trusted. But Noelle couldn't take such risks. If anyone came with her, their lives would surely be cut short. Noelle couldn't allow that, she wanted to give them all their best chance. "I fight to protect them. And so, I'll do just that tomorrow." She was determined to save everyone from Chara. Yet, her eyes were glowing purple. Noelle was obviously afraid of the upcoming battle. She didn't want to die. After a moment of thinking, Noelle went back to her room. She sat at her desk, took a sheet of paper and started to write.

The next day, in the late afternoon, Noelle decided it was time to go. She had spent the first part of her day to chat with her parents and Sans, paying a visit to Gaster and the twins, and even giving a phone call to the Dreemurrs. Noelle wanted her whole family remember her being social and in a good mood, in case the final battle had to end badly. She wanted to remember everyone too, and to live a good time with them all before going to face her fate. That way, the good moments wouldn't be tainted by sad feelings. And now, it was time to go. Noelle put a letter for her family on the coffee table, then went to the front door. But before she exited the house, she gave one last glance around her, mentally saying goodbye to her home. Then she left, taking the magic sword with her. Noelle walked long the street and out of the village without giving a second glance back. Because if she did, she would crack and cry. She had to stay strong. Noelle then noted that she still had a bit of time before the Sun would start to set. So, before going to the place from her vision, she took a turn in another direction. In a calm and isolated place outside a wood, there were six anonymous tombstones. Only a heart of a different color was represented on each tombstone. Noelle opened the wire gate and stood in front of the six tombs. After a moment, she spoke up.
"Hello. I'm sorry I didn't bring any flowers... I'd like to promise that I'll bring some another time, but… I'm not sure if there will be another time. That's right… I'll maybe die today. If you watch our world from… wherever you are, you already know how it'll happen. I might get killed by Chara, the first human to fall in the Underground, a child not that different from you all. Isn't it crazy? ...Well, in fact I cannot be so sure. I don't even know your names…"
Noelle paused, feeling like her heart was being squeezed. There was also an unpleasant knot in her throat. She blinked several times as she felt tears coming.
"Is... Is that normal how I feel now..? I feel like… like I'm being pushed to walk the plank… to be drown in the depths of the ocean… and unable to swim up to the surface, since my hands are tied… This is basically how I feel like right now. Did… did you feel the same before you faced Asgore..? How is it like to die?" - tears slid down Noelle's cheeks - "I... I don't want to die..! Why must I die so soon..? There are yet so many things I didn't have the time to do and I'd still like to do…"
Noelle then sniffed and whiped away her tears. She smiled sadly and pursued.
"Ha ha... I'm complaining that I'm dying too young, while you were much younger than me when it happened to you... And yet, despite being older than you were isn't that comforting… It still feels like my death is coming too soon. But honestly, I prefer die myself than seeing those I love being killed. This is why I'll fight to the end… no matter what it's like."
A glimmer of determination sparkled in Noelle's eyes, despite the sadness of her look.
"Can I just ask you one little favor? Can you please… be there when everything's over? Can you welcome me to wherever I go after I leave this world? I'll certainly need some company, and yours will be the most welcome."
After another moment standing in front of the tombstones, Noelle turned around and started to walk to the spot where the final battle was meant to happen. When she arrived, Chara was already there.
"You are late." - she commened.
"No, I'm not. Maybe you are too impatient and are in advance?" - Noelle suggested.
"It doesn't matter." - Chara grumbled, taking her favourite knife - "Shall we get started? I'd like to say it'll be fun, but I'd be lying."
"Don't try to intimidate me." - Noelle said, as she pulled out her sword - "I'm accepting my fate, whatever it is."
Before they started to battle though, she summoned a row of bones to prevent anyone who'd want to interfere from reaching her. Noelle knew it was only a matter of time before her family found the letter… if they aready haven't. The two women then looked each other in the eyes, and took a ready to fight posture. The final battle could begin.

Meantime at home, as Papyrus was dusting the living room, he saw a paper lying on the coffee table. Papyrus picked it up and he gasped in horror as he realized what it was. It was his daughter's farewell letter.
"OH NO... NO, THIS CAN'T BE..! NOELLE, SILLY, WHY ARE YOU DOING THIS..?" - he said as his eyes glowed purple.
"hey, what's with that face, bro?" - Sans asked, as he popped up on the couch out of nowhere.
"SANS, THIS IS TERRIBLE! IT'S NOELLE, SHE WENT TO FACE CHARA BY HERSELF!" - Papyrus said with alarm.
"what?!"
"IN THIS LETTER, NOELLE SAYS HER GOODBYES TO EVERYONE AND SHE APOLOGIZES FOR NOT TELLING US ABOUT IT. SHE SAYS THAT SHE JUST DIDN'T WANT CHARA TO HURT US..! SANS, SOMETHING CAN BE DONE, RIGHT?"
"no matter what noelle thinks or says, we shall look for her!" - Sans said, his left eye glowing blue brightly.
At that moment, the front door opened. Frisk and Asriel entered the house, holding big bags of groceries. As soon as they stepped inside, Frisk immediately saw that something was going on.
"Papyrus..? Sans? What happened?" - she asked.
"FRISK! NOELLE WENT OUT BATTLE CHARA!" - Papyrus replied, walking up to her.
"What? Alone?!" - Frisk gasped, almost dropping her groceries.
"What was she thinking?! She could get herself killed!" - Asriel exclaimed.
"SHE KNOWS THAT AND THIS IS WHY SHE WROTE A FAREWELL LETTER..." - Papyrus said, showing the paper to his wife and Asriel.
Frisk took the letter and she quickly read it in her mind, whith Asriel looking over her shoulder. Frisk looked up at Papyrus with a pale and terrified expression.
"LET'S GO FIND OUR DAUGHTER, FRISK." - Papyrus said, taking Frisk's hand in his own - "WHATEVER SHE THINKS TO BE THE BEST, WE AREN'T LETTING HER DOWN."
Frisk nodded with determination. Asriel quickly moved the bags of groceries in the kitchen, before coming back and saying:
"I'm coming with you. After all, it's with me that everything started. This is maybe my last chance to fix things."
"alright, so let's go?" - Sans asked.
"WAIT, SANS. I MUST INFORM GASTER ABOUT THIS." - Papyrus said, as he already started to type a message in his cellphone.
"why telling gaster about this?" - Sans raised an eyebrow.
"SANS, IN HIS SHOES YOU WOULD'VE LIKED TO KNOW."
Shortly after sending the message, the group went out of the house to look for Noelle. They just hoped they would find her in time.

The battle between Noelle and Chara was pretty intense. This time, it wasn't all bloody like when Noelle unleashed all her anger three days ago. Instead, it looked more like a knight of light was fighting to stop a demon. Noelle used just her sword, no magic. She would use it to either make Chara lose her balance, or she'd turn it into a shield to protect herself from a too dangerous move. As the battle kept going, Chara was getting more and more frustrated. Until at some point, she asked:
"Why are you barely fighting back?! Fight me! Give everything you have! Why don't you let your anger lead you? Where's your magic? Where's your determination?!"
"My determination's intact, don't worry! I just use it in another way!" - Noelle replied, as she managed to make Chara drop her knife for a few moments - "You expected that my rage would blind me? Well, sorry to disappoint you. It's not happening anything soon… or ever."
Chara picked her knife from the ground and charged at Noelle, who dodged like a pro.
"Because I don't fight to kill! I fight to protect those I love!" - Noelle kept going, while shielding herself from the attacks - "Because I just want the world to live in peace. I only want help people find the light in the darkest hours!"
"What a pretty speech! Come on, you don't actually believe the crap you just said, right?" - Chara said with a grin - "Here you are, facing me. You might die here from my hand at any moment, all alone. You live only to save the others, just giving and giving, without ever getting anything in return from them. Where is your light, Savior?"
Noelle quickly dodged Chara's attack, falling on her knees and almost losing her hold on the sword. Chara's question was meant to make Noelle doubt. But instead, it brought up only good memories. Noelle stood up, her eyes glowing pink. She remembered the day when she reunited with her parents for the first time after many years apart. She could still feel the warm embrace around her.
The memory filled her SOUL with... love.
Tightening her grip on her sword, Noelle took a posture indicating she wasn't giving up anytime soon. She remembered the Gyftmas Eve, when Sam and Piper gifted her a mug with the word "Mommy" and asked her if they could call her "Mom" from that day on. The bond between her and the children she once gave up had reached the ultimate level.
The memory filled her SOUL with love.
Chara charged at Noelle, who fearlessly moved her sword and made Chara fall on the ground, dropping the knife in process. Noelle recalled the moment when she and Asriel unfused. She had spent days inside his body and during all that time their consciousnesses were interweaved, which permitted Noelle and her uncle Asriel to understand and support each other. Forgiveness led to a new friendship.
The memory filled her SOUL with love.
Chara glared up at Noelle, after seeing that her hand had a deep cut and was bleeding a lot. She charged at her, intending to punch her in the face with her fist. But Noelle dodged quickly, making Chara fall on her stomach. Noelle remembered a faint and distant memory from her tender childhood, when Toriel sewed her the Delta Rune dress. The memory was too distant to remember things in details, but Noelle was pretty sure that Toriel's voice was saying something about her looking like a true princess. It was a moment of pure grandmother's kindness and admiration. And Asgore… he's always looked at her with pride, and gladly spent his time to teach her more things about their kingdom.
The memories filled her SOUL with love.
Noelle made a step towards Chara, who shakily sat on her knees. Noelle remembered how she met Sans in Undertown. As well as all the interactions they had together. Whenever she felt down, he'd make her laugh. It was simple, but not unsignificant.
The memories filled her SOUL with love.
She then remembered about how she helped Gaster to face Asgore when confronted about his crime. And then, how he helped her in return, saving her life when her SOUL had been absorbed by Flowey. Things had never been easy between Noelle and Gaster, considering how roughly things started. But even though Gaster barely expressed what he thought of her, Noelle could see by his actions that he did care for her. More than he dared to admit, actually. And Noelle grew fond of him too.
The memory, once again, filled her SOUL with love.
Among all the memories, Noelle also recalled the tune played by her music box. She vaguely remembered the lyrics that song Frisk used to sing to her years ago. The song was about hope and not being alone in the darkest hours.
"I am not alone, and I have never been." - Noelle said with a strong and confident tone - "No matter how far away my family is, their love is still there with me. They are the light that guides me through darkness. They give me more than I could ever give them. Yes, I might be a powerful Savior, but it's their love that is my guide on the right path."
All the love that filled Noelle's SOUL then evolved into something powerful... Noelle's SOUL got filled with pure MAGIC.
"That's what makes the difference between you and I, Chara. And I can't help but pity you."
"Shut up! Don't you dare pity me!"
Chara kicked Noelle in the stomach, making her fall on her back a few inches away from her spot. Before Noelle got the chance to stand up, Chara had the time to pick her knife from the ground and rush to her. Luckily, Noelle dodged her attack by rolling aside on the ground. She quickly picked her shield and protected herself before Chara's knife could hit her.
"Shut up, shut up, shut up!" - Chara was yelling, having completely lost all control of herself - "Shut up about love, shut up about hope, just shut your freaking mouth!"
"Noelle!"
It was Frisk's voice. Both Chara and Noelle froze. They looked aside, to see behind the barrier of bones the Savior's family being here. Frisk, Papyrus, Sans, Asriel, Gaster, Sam and Piper were there, staring with alarmed looks. Noelle was beneath Chara, her shield placed over her upper body like a turtle's shell. She wasn't in the best posture. Chara, who was on the top, almost dropped her knife in surprise and irritation. For a short moment, she was stoned. Noelle used the opportunity to push her away and stand on her feet. She turned her shield back into a sword, while Chara growled:
"I thought my condition was pretty clear..."
"I swear I didn't call for them! Please don't harm them..! They... they probably came because of the farewell letter I wrote for them..." - Noelle then looked at her family through tears - "I'm so sorry about this… But I just couldn't bear the idea of you being hurt…"
Everyone looked back at her with equally moved expressions. Chara's body started to tremble. Noelle prepared herself, expecting another attack. But what happened next wasn't an attack. Chara let out a loud shout.
"I hate you! I hate you, Noelle Dreemurr!" - she yelled.
At that moment, when the two gazes met, Noelle almost gasped at what she saw in Chara's eyes. She understood.

Fourteen years ago...

Noelle rushed in the house of her foster family, her clothes and hair soaked wet. As she went up the stairs to go to the bathroom, she could distantly hear the foster father say something about leaving a trail of water behind her, but she didn't care. Noelle locked herself in the bathroom, undressed herself from the wet clothes and opened the tap of the sink. A few minutes ago, she's been beated up by two classmates for not having let them copy her homework. She'd been lying on the ground under the rain for a few minutes in despair. Noelle had a few bruises on her upper body, but also many scratches on her hands and face. (A result from being thrown into a rusty wiring.) She started to wash her hands with soap and winced when the scratches stinged. Then, she started to wash her face to get rid of the dirt and the stains of tears. When she whiped her face with a towel and looked at herself in the mirror, she flinched. For some reason, Noelle didn't recognize herself. But why..? The scratches weren't this bad, it would heal in two days or so. So what changed in her face? After a moment of contemplating herself, Noelle realized that something was different about her eyes. Yes, they still had the same shape and color, but… something was missing. And as soon as Noelle figured out what it was, she started to cry again. She stood there in front of her mirror, crying rivers of tears. That same morning yet, she still had that glimmer of faith in her eyes. But now, it was gone. Because a few minutes ago, Noelle realized that her parents would never come for her, like she kept hoping those past nine years. And when the realization hit her, something just died within. It was like some light in her heart was snuffed out. When Noelle finally came out of the bathroom, she walked up to her bed. She pulled out her old drawing. The paper was in a poor condition and the colors lost of its brightness. Yet, Noelle kept it with her all those years to feel loved by her parents. But now… Noelle no longer believed in them. Her eyes filled with tears and her heart with grief, Noelle ripped the drawing in pieces.

Present day

In Chara's eyes, there was something that Noelle had seen in her own eyes before but that was gone for a few months now. Noelle kind of forgot her former pain, she was so used to have all the wonderful people in her life, that she didn't notice the change in her look. But it was a look that she never truly forgot. But that same look was definitely there in Chara's red eyes. Noelle saw that in front of her was standing a woman who was devoided of everything: she had no hope for a better future, no faith in anything good to happen. No (actual) dreams that she could try to accomplish. It was because she was deprived of all those fundemental things which built any person that Chara became a "demon". She was just empty. And for once, Noelle felt empathy for her.
"I hate you!" - Chara's words reasoned in Noelle's mind.
"Chara..." - Noelle breathed out - "And I... I don't hate you."
Those words made Chara give Noelle a weird look. She was surely wondering if she heard correctly. Noelle looked straight into Chara's eyes to tell her that she really meant it.
"Chara, I know exactly how you feel... I know how it's like to be deprived of faith. I went through this and it's very painful. But it's never too late to regain faith. But you must allow some light to cross the door of your heart."
Then, to everyone's surprise, Noelle threw her sword aside. She heard her family members call for her, but she didn't turn her head to them. She kept looking at Chara and pursued:
"It's not too late to turn your life around... You can still start everything over and leave all the pain and darkness behind. All you have to do is to make the right choice. That choice... is entirely yours. I'm not fighting back. What happens next is up to you, Chara."
"And what if it is too late for me?" - Chara asked, looking away - "What if I just can't make the right choice anymore?"
"Let's give it a test..?" - Noelle replied, a single tear sliding down her cheek.
A moment passed. Then another. Chara didn't move for a while. The Sun almost completely set. Chara tightened her grip on her knife, before rushing straight at Noelle.
"No!"
"NOELLE!"
"Mom!"
"Chara, stop!"
"Noelle!"
Those were the cries Noelle heard before seeing the silver blade move quickly right in front of her eyes.

A/N: So, the flashback when Noelle barely recognizes herself in the mirror takes place right after the memory Asriel saw back in arc 2. The moment that I call "Disbelief Noelle". (The phrase saying that Noelle no longer believed in her parents is actually a reference to Disbelief Papyrus.)
And yeah, the "Don't Forget" song from Deltarune exists in this universe/timeline! I just think that the song is beautiful and that it would be something a very young Noelle would need to hear from time to time. This was what, on a subconscious level, helped her to have faith for nine years. Otherwise, she would've been more scarred inside than she is. Oh, and the nightmare she's had was actually a vision of the near future.
The reason why Noelle went talk to the six SOULs before facing Chara is a purely human reaction. I mean, she's certainly about to DIE and she's naturally scared. Of course she needs to speak up her feelings! But since she didn't talk about it with her family, she turned to the fallen humans who certainly know how it's like to die prematurely.
Noelle hid the information about the final battle not because she hadn't learned anything from previous exprience! It was because she deeply cares for everyone and knows how far Chara would go if she disobeyed. And provoking a demon is a VERY bad idea.