Underwing

by Meatbun Attack

The prophecy never mentioned two angels. Then again, Prophesies tended to be vague like that, and in its defense, the second believed angel really wasn't as relevant to the Prophecy as the first one. That doesn't mean that he wasn't important, though, nor that he didn't bring change in the wake of his wings. (Byakuran entering Underground) Epilogue will come sometime to wrap it up.

9. Asriel

I'm so sorry for the long delay... I have this chapter to blame and my own insecurity...

The first version of this chapter wasn't good in my opinion, that it had too many jumps. Second version of this, I felt like I screwed up the third POV with how I was focusing on everyone at the same time. Third version, I screwed it up again by constantly changing the view. And then, I wrote out this chapter. To say that I wasn't sure how to write Third POV in this situation is a clear understatement. In my opinion, this chapter shows that I'm not used to this writing style...

But last chapter everyone! This one is way longer than all the other chapters I've written. (about three times longer...) I hope you enjoy~.

(Guest reviewer Prince, your review made me smile for a whole day. It was so awesome. XD)

OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

Byakuran meets a child on his way to the castle. He found it strange how empty it was, but now he understands why. When Byakuran is about to enter the elevator leading to the castle, the door opens and a small goat child steps out. He must stop and blink a few times, staring at the child as they do the same. He has a vague memory of seeing this child before, way back when the last true ending took place.

So he smiles at the child in greeting, because he can't exactly lift up a hand while they are occupied keeping him stable. And he gets the feeling he shouldn't show this kid what he's holding.

"Yah, kid. Nice to see you again. Good to be walking on two legs?" Byakuran doesn't know why he said it, but it just felt right. He knows this kid, that much is certain. That nagging feeling always pops up whenever he meets someone he knows from a parallel world, but this nagging is deeper that that. The kid smiles awkwardly, scratching the back of his head while looking down to the floor.

"Y-Yeah, it is. I never thought you would come too, Byakuran."

When the kid looks up again, he spots how Byakurans fist is clenched tightly and is holding up his entire body weight. The child immediately gets worried over him, stepping out from the elevator to approach him with his paws slightly raised in the air like he can catch Byakuran if he falls. But the child is way too small to catch someone as old as him, even if the monster have lived longer than he has.

"What's wrong? Has something happened to your soul? Is it because of the RESETS?"

"No, no, nothing like that." Byakuran says, shaking his head as 'no'. He opens his eyes to stare down at his chest, still concentrating on protecting his core, but his flames will soon run out. Again. He needs to find some way to end Gasters constant nagging. Since his headache is gone, he should be able to come up with something if he tries. "It's not because of the RESETS, but if I don't get to the surface soon, I'll probably die."

The magic doesn't falter in trying to get past his defences. Gaster has stopped hesitating completely. Some of the few flames he has left manages to escape through the crack and makes his body even warmer. With a twitchy smile, Byakuran places his forehead on the stone wall in hope that it will cool him down. The heat just increases when his concentration is momentarily broken and even more flames get out into his flesh.

The child chokes on air when he hears this, staring at Byakuran with huge, shocked eyes. Byakuran, the person Chara was never able to defeat, the person who had so many plans when he acted in this world. He is going to die?

"D-Die? B-But-! Y-You can't-! This is bad… H-Have you stopped the power to reset already? You must have, haven't you?"

Byakuran looks back at the child, flinching slightly at a powerful blow to his core before he regains his composure with a smile aimed towards the goat child. His body temperature is very warm and now he is really grateful that he took off his long sleeved shirt back at the lab. But he had to keep his vest, he has important stuff in its pockets. Byakuran has a strong feeling that this child could be the solution to all of his problems, but he doesn't know why. He doesn't remember their name either, but he is certain that when he does, he'll remember why this Child is so important.

"No, it wasn't that easy. Now, the power is trying to destroy me for trying." Of course, that is a lie. The reason to this magic is attacking him stretches a lot further than that. Such a reason would be way too simple for it to be the reason why Underground's strongest magic in the air is pressing down on the core of his powers. But the child doesn't have to know about that part. Just hearing that part of the power trying to destroy him makes the boy even more worried and frightened. The child puts a hand to his forehead and looks down at the floor.

"N-No… B-But then… If the power is still there, then the world will still reset… And if you still survive that, you'll be a a lot weaker than usual. A-And now that I know…" The boy looks up at Byakuran with tears in his eyes, expression twisted in worry and despair. He is really worried for Byakuran. "W-When I become a flower, I'll hunt down and kill you!"

That triggers a memory in his mind, a very important one. This child is Asriel, son of king Asgore and queen Toriel. The child who died, lost their soul and got resurrected by Alphys as a flower without a soul. Without a soul… Asriels core is empty. He can absorb both human and monster souls. That might just be the solution he needs. So with his smile widening and a small laugh escaping him, he heaves himself up, staggering slightly before he is able to stand straight in front of Asriel. Byakuran puts his free hand on top of the child's head and ruffles his fur gently. While he does this, Byakuran discreetly looks over Asriels core.

"Don't worry, Asriel-kun. When you said that… It actually gave me a great idea." The child stops crying, looking curiously up at the man. Byakuran feels the magic pause slightly, knowing that it is Gaster, the ghost must be curious over this conversation. So with the attacks paused, Byakuran quickly continues to explain his plan before Gaster starts to attack him again. When he feels his legs trembling, he must remove his hand from Asriel and put it back on the wall so he won't collapse.

"Asriel-kun. Would you like to have a soul again?"

Asriel's eyes widen even further, his body relaxing completely due to shock. He stares as if Byakuran has grown two heads out of nowhere and started to dance a weird dance. The thought of Asriel gaining a soul just like that seems impossible to him, unthinkable and foreign. He needs to steal someone else's soul to get one of his own. He immediately feels panicked when that thought enters his mind and he tenses up, clenching his paws into fists as he stares determinedly at Byakuran.

"No, I can never take your soul, Byakuran. You have done way too much for this world, for Frisk, for me to take your soul. You have people to go back to and I-."

"I wasn't talking about my soul, Asriel-kun." Byakuran interrupts with his eyes closing when his smile grows wider. The magic still hasn't attacked him yet. "This little problem with resets is magic that's alive. It needs somewhere to stay and I think you'll be the perfect candidate." He stares seriously into Asriels eyes to make him keep quiet when it looks like he's about to say something. "Of course, all energy can't enter you, that's way too much, but at least enough so it won't affect the whole world and make it keep its constant time loop. The energy would gain consciousness within your core and make it strong enough so you'll stay in that form. The both of you have one part, but not the other. There are a lot of things that could go wrong by doing this, but it's better than any other option."

This child… Is also half of a whole…?

Byakuran can't help but smirk slightly when he hears Gasters response, pushing off the wall to move into the elevator. Byakuran needs a reference, and what better reference is there than Asriels father? The child is so deep in thought that he doesn't notice Byakuran entering the elevator, which is good for Byakuran since he stumbled and forgot to hide what he's holding. The pressure of Gaster is gone now from his core. Not completely gone, but now it's helping him. Gaster is making sure no more of his flames are escaping. His once single crack is now all over his core, he won't be able to use his flames properly until he fixes this.

"A-Alright…" Asriel whisper, looking up to where Byakuran last stood. The child is confused for a few seconds until he turns to see Byakuran leaning against a wall in the elevator, one arm raised weakly and pointing to the floor button.

"Good. So let's go up so I can get a reference."

Asriel feels doubtful about seeing other monsters, he was supposed to leave before everyone woke up. He isn't supposed to break their hearts by showing up and then suddenly become a flower again. But if Byakuran can give him a soul, then… Would it be worth it…?

"B-But I can't see them. What if it doesn't work and I just turn back into a flower? They would be heartbroken! I can't do that to them."

When the child sends him a fearful glance, Byakuran smiles what he hopes is an encouraging smile. He understands how Asriel feels, afraid of what the ones he love will think of him now that he's coming back to them. It's somewhat similar to how Byakuran felt when he decided to fight for Yuni in the arcobaleno battles. But he needs just one last push. It needs to be done.

"Even if this doesn't work, it would mean the world to them if they would be able to see you again."

Asriel is still doubtful, staring down at the floor and shuffling his feet. How can Byakuran be so sure about that? Maybe his mom and dad have forgotten him. It's been so long after all. And he isn't even the real Asriel, he's a flower with a piece of Asriels soul and all of his memories. He's just a replica. Will they really love a replica? Will they really see him as Asriel? He doesn't have a soul… But if he goes with Byakuran, he might just get one of his own. But will it really work? If not, it would be better for him to just leave. No matter what Byakuran says, it isn't worth showing himself and then break their hearts immediately after.

Byakuran sees Asriels hesitation and sighs tiredly. He doesn't have all the time in the world, but Asriel needs this. If it feels like this is his own choice, then he won't complain about what Byakuran will do. If Asriel doesn't step in now, he'll use force.

"Asriel-kun. I am the person who knows more about this power than anyone in any parallel universe. I have more knowledge than you can ever imagine about what you call magic, which is really an alternative version of human's 'determination'. Once, I had the power of a god and have destroyed the world more times than you would be able to count. I can become the most powerful being you can ever imagine and you are doubting me on my ability to successfully give you something as simple as a soul using the energy around us?" Byakuran puts on an easy going smile, his serious mood dispersing like a leaf floating down a stream. "I must say, I'm a little hurt to hear that. Don't you trust me?"

Asriel actually feels more uncomfortable than he's ever been in Byakuran's presence. The thought of Byakuran becoming a god, that thought is actually possible. But for him to become more powerful than Asriel was just a few minutes before? That thought is downright frightening. Can that really be possible? What would he have to do to gain that much power to destroy the world? How many people would he have to kill, to consume, before he becomes a god? Can a human really absorb another human? But that seems impossible, it is impossible. And when he talks about parallel worlds… does he mean there are other worlds than this one? That seems impossible as well, it can't be possible.

Asriel is brought out from his thoughts when an invisible force pushes him inside the elevator, the doors closing behind him when Byakuran presses the button that will take them to the castle. Asriel wants to leave, since meeting his parents would only bring them and him more pain in the end, but at the same time what Byakuran said is partly true. He knows more about magic than anyone even if he isn't from Underground but has never shared his knowledge with Asriel but only given him small hints to that he knows about it. With Byakuran's help there is actually a chance that Asriel might get a soul, his own soul without having to kill or steal anything for it. This thought makes Asriel smile and relax. He will do this, he will actually get a soul.

As the elevator is taking them up, Byakuran has his eyes closed and is thinking of different ways he can break to the news to all the monsters who will be present. He also puts a lot of focus to pulling back his flames into his core and using the majority of it to fix the deeper cracks in his soul. He grips onto the syringe a little tighter, he will need to use it again once he can sit down.

"Byakuran? W-We're here."

Asriel is fidgeting at the door for the elevator, a nervous smile on his face directed to Byakuran. The human nods, stands up straight with a little wobble before he walks out with the goat child. Asriel gently takes hold of Byakurans hand and lead him forward, giving the human the only support he can. Byakuran can't help but smile slightly, focusing more on keeping his core intact now that he doesn't have to focus as much on walking. He's running out on flames, he need to use it now. But Asriel can't see…

Byakuran stops walking and focus on his surroundings. They've made it to the middle of the yellow corridor. Or 'judgment hall' as Sans likes to call it. This will be a good place. He'll get some time alone while Asriel runs off to get the monsters. He completely ignores anything Asriel is saying and walks closer to a pillar, sitting down and leaning his back against it. Groaning softly at the ache in his body, Byakuran opens his eyes to give Asriel a small smile. The child is at the brink of tears and is hovering his paws in front of him in worry. It's adorable.

"I can't walk more… Once I get some rest, I'll be better. But I don't have much time. You go on ahead and get them, but not Toriel. She wouldn't handle seeing you get hurt when I give you a soul. Asgore is important though, I need him as reference."

Asriel stands there for a few more moments and opens his mouth as if he's about to protest. Byakuran gives him a glare, which silences the child and makes him look down at the floor. He's shaking in fear, even more tears gathering in his eyes. He's absolutely terrified of the thought of meeting his parents alone.

"Asriel. We don't have time for small doubts. You need to go." Byakuran says sternly, adjusting his grip on the syringe. Asriel can't see it, he would try to stop him. Byakuran needs to be alone.

Asriel clenches his eyes shut tightly, letting a few tears run down his face as he nods. The child then quickly runs off towards the throne room where everyone else will be. Once Asriel has turned his back on him, Byakuran adjusts his position and takes a deep breath. He holds up the syringe to his face, the glowing rainbow liquid inside shaking through the tremors in his hand. He doesn't like this, but it's the only way.

"Gaster… Would you mind helping me this time instead of using it against me? I can't get you inside his soul with how cracked my core is." Byakuran says to thin air, pointing the needle of the syringe towards his chest. This substance includes magic to keep it in a liquid state. But at least he is able to separate magic and Dying will flame, so no magic gets into his core. After a few moments of waiting in silence, Byakuran finally gets his answer.

… Alright. I will remove the excess magic from your body. If you hadn't done this previously, I would have told you to stop this madness.

Byakuran laughs slightly, making the needle pierce his skin without as much as a flinch. So now that Byakuran is willing to help him, Gaster cares about his safety. Well, Byakuran would do the same but that is beside the point. Maybe he and Gaster are more alike than he would like to admit.

"True, I would call myself crazy too. But…" Byakuran slowly inserts the liquid inside his body, his body temperature immediately increasing as Byakuran absorbs the flames. "If I weren't so good at controlling my flames, I wouldn't have seen this as an option either."

He can immediately feel the change from last time he did this, instead of the magic within the liquid trying to get into his core through the flames, the magic is separated and moving towards his skin. It is a lot easier to separate the flames and magic with Gasters help so Byakuran can focus more on converting the different flames into sky flames than actually separating them.

Then it's good I know so much about magic, being a part of it can be useful in this situation.

Byakuran agrees silently, closing his eyes in focus so he won't make any mistakes. He throws away the empty syringe, making a loud clanking noise echo across the long corridor. Soon after the syringe is empty, Byakuran can hear voices approach the corridor he's sitting in. The new flames he has acquired are a huge help in mending together the cracks in his core, but there are still a few small ones left. Although, those will need to stay that way, Byakuran will use the rest of his flames to make sure Gaster enters Asriels soul. It might be a long process. Byakuran opens his eyes slightly when he hears his… Friends entering this Judgment hall. Can they really be called his friends? Byakuran can feel the excitement coming from the magic around him. Gaster must be absolutely thrilled at the thought of getting a body again.

Byakuran glances in the direction of the voices, seeing a distressed Asriel with everyone else in tow behind him. Including Toriel. The magic that Gaster is pushing out from his body is swirling around his limbs in a mix of yellow, purple and green. Must be one worrying sight for the monsters to see.

"Make sure to do exactly as I say, Gaster. Or else, you might destroy his core."

Gaster agrees silently to Byakurans whisper and the human puts on a cheerful smile for all monsters approaching him. His voice will be able to reach them with how much this corridor echoes.

"I thought I told you to only bring one parent, Asriel-kun. I didn't expect such a huge party to join us. I would have brought my marshmallows."

Asriel is not at all pleased at his playful tone and he shows it by lightly hitting Byakuran over the head once he has gotten close enough. The prince is already crying, but it's not out of fear for himself. But fear for Byakuran. This makes the human smile softer at him even after he was hit.

"Stop pretending you're okay! You're not! We're all really worried about you."

Byakuran chuckles lightly, glancing up at the older monsters who have now reached him as well. All of them do seem worried, Alphys nervously staring at the magic evaporating from his body.

"Maybe you are worried, but this won't kill me that easily." That's a huge lie, he was at the brink of death just a few seconds ago. "Now, I will ask everyone but Asgore to leave. You could exit the barrier and look around, the surface is really beautiful."

"Like hell we can do that when you're like this!" Undyne screams out, clenching her fists tightly and glaring down at the human. Byakuran just smirks, closing his eyes. Now that Undyne has voiced her opinion, Papyrus will voice his after and then Alphys and the family of goats. They'll try to convince him to make them stay, that they will be here to support him and Asriel. That he should tell them exactly what's happening to him. It wouldn't be good for them to know.

"THAT'S RIGHT! I CANNOT LEAVE ONE OF MY FRIENDS WHEN HE IS IN THIS STATE! WE SHALL REMAIN HERE SO ALL OF US CAN GO TO THE SURFACE TOGETHER!"

That's Papyrus.

"Y-You're right. B-Besides, I-... I'm worried about t-that magic around you. I-I have to stay to make s-sure nothing goes wrong."

That's Alphys. Now, Toriel will speak up her opinion while treating Byakuran like a fragile child.

"no, your majesty. he won't change his mind."

Byakuran opens his eyes and look up at Sans, his pupils are gone again. The human can't help but let out a small chuckle. Once again, Sans is the unpredictable one. But from Toriels expression, Byakuran was at least right that the goat monster would try and convince him with her motherly ways.

"Sometimes, I wonder who knows the other best Sans-kun. You or me."

Sans shrugs lightly, closing his eyes with his posture slouching a little more when everyone's attention turns towards the skeleton. Well, almost everyone with Frisk trying to stay awake and Asriel shaking their shoulders gently. But Byakuran is thankful that Sans managed to quiet down the protest with just two sentences.

"it all depends on the situation I guess. but what have you planned this time? is it some kind of secret?"

"No, nothing like that." Byakuran says quickly, holding up a hand when everyone are now looking at him with curiosity in their eyes. "I simply believe that this would go best with as few people present as possible. You see, Asriel will be in a lot of pain while I-."

"What!?" Toriel interrupts angrily, her hands being set aflame with her magic. Asgore holds up his hands in front of his ex wife to try and calm her down, but Toriel shoves his hands away from her to continue glaring at Byakuran.

"Tori, calm down and let him-."

Toriel silences him with an angry glare, her eyes practically burning in anger. Seeing Toriel this angry immediately makes the king freeze up. Toriel haven't looked this angry since their argument right before she left for the ruins.

"Don't you 'Tori' me! He is going to hurt our child! How can you be fine with that?! He's going to hurt my Asriel for something he thinks is necessary! And he won't even tell us what he will do!"

Asgore holds up his hands, a frown on his face. He isn't fine with Byakuran hurting his child either, but from what he has learned, this 'angel' would never do anything without a good reason. Byakuran has so far given the monsters hope and helped out in various parts of the kingdom. Simply listening to what he wishes to accomplish is something he can do as repayment. He can't take a decision before heading the whole story.

Asgore is just about to tell this when Byakuran interrupts. He feels that this will go nowhere if it keeps up, Asriel needs magic to get a complete soul before he transforms into a flower again.

"So you would rather have Asriel be a shell of your son, who will disappear in a few hours, than let him feel the pain necessary for me to create a soul for him? My, what a bad parent you are."

Hearing this, Toriels anger dies out as she stares at Byakuran with wide, confused eyes. She couldn't possibly have heard right. Bad parent? That may actually be true since she couldn't save any of her children from death. Give him a soul? But he's right there, her own little boy just like he was before death. Asriel has a good soul, right? He must have or he wouldn't be back.

"C-Create a soul?!" Alphys bursts out in shock, her claws shaking in nervousness. She remembers last time she tried to repair a monster soul, it became her biggest failure. And Byakuran thinks he can create a soul? "T-That's impossible! To c-create a soul, a specific amount of m-magic has to be c-compressed w-within a s-shell which is the core of the soul! N-No one knows w-what this shell can possibly be made of a-and you don't have t-the necessary magic n-needed to-!"

"What-... Why is this...? W-Why is this here…?" Someone to the right asks and everyone turns their head in that direction. Asriel is holding something in his paw, staring at the object. The goat child is trembling slightly, his eyes wide in fear. He remembers this, the thing Alphys used on him to make him a flower. He still remembers how this rainbow liquid was injected in the flower to give him life. And right now, he's holding a syringe with drops of this liquid inside of it and the needle wet like it was just used. Byakuran couldn't have…

"WHAT IS THAT YOU HAVE, GOAT CHILD?" Asks Papyrus and gently plucks it from his hands. He also picks up Frisk and tuck her into one of his arms since it looked like they were about to fall asleep standing. Frisk adjust themselves and quickly fall asleep in the skeletons arm while he inspects the syringe. When he spots the rainbow liquid, Papyrus brightens up in wonder. He has never seen anything like this.

"WOWIE! THERE ARE SO MANY COLORS! THIS LOOKS LIKE THE 'RAINBOW' IN MY BOOKS! EXCEPT ITS FORM IS NOT A HALF CIRCLE."

"Rainbow…?" Alphys mumbles, her eyes widening as she stares between Byakuran and the almost empty syringe. Byakuran answers the silent question with a wink and Alphys's eyes widen even further in horror. That's why he is glowing softly like that, his body is adjusting to the injection.

Undyne takes the syringe from Papyrus and studies the liquid as well. She raises her eyebrows when no matter how she turns the holder, the liquid still holds onto its arrange of colors. This is science stuff, she has no idea what this can be. So she looks towards Alphys to try and get an answer from her but quickly stops herself from asking when she sees how much Alphys is trembling. She has walked away slightly from the group surrounding Byakuran too. With a worried frown, Undyne walks over and puts a hand on the scientists shoulder. Alphys jumps in surprise, head turning quickly towards Undyne with a slightly panicked look in her eyes.

"Hey, Alphys. Are you ok?"

Alphys quickly nods, looking down at the ground. But she then remembered her promise, that she shouldn't lie anymore, and shakes her head instead.

"No, I'm not… That liquid… It's dangerous…" She whispers softly, hugging herself as she remembers what it did to all those monsters she wanted to save. Undyne squeezes her shoulder a little tighter as a sign of comfort before she looks around.

Toriel and Asgore are talking, Asgore seems to try and assure her of something but Undyne doesn't know what. It should be about their son since the queen seemed more upset about all of this than Asgore is. Sans is talking to Papyrus, the taller skeletons voice still enthusiastic and loud. It seems like they're talking about Frisks condition as they're sleeping in Papyrus arm. Asriel, the goat kid, is standing close to where Byakuran is sitting. And that guy is just sitting there, smiling like nothing is wrong while he's giving off that weird glow over his whole body. Didn't Asriel say Byakuran was about to die? Then how can he sit there with a smile on his face?

"Oh no…" Alphys mumbles, putting her claws on each side of her head in horror like she just came up with a horrifying thought. Undyne quickly looks back to the reptile and play close attention to what she's saying. It's almost like Alphys has forgotten Undyne is there with how she's mumbling.

"T-That's-. I-It has to be too much-. H-He's-. Oh no, what can I do? I-... I-I would just screw it up."

Noticing that Alphys is getting way too worked up for her own good, Undyne drops the syringe she's still holding and crouch down in front of Alphys, putting her hands on either side of her face. Once Alphys is focused on her, Undyne gives her a wide grin in hope to calm her down. Even if Undyne isn't a scientist person, she can connect the dots easily enough. But she has absolute confidence that Alphys will be able to do anything related to science if she puts in all her effort into it.

"Hey, calm down. There's nothing to be worried about. You're great at this science stuff, so you'll be able to do anything. He's just going to make that soul and then you can do a check up on him. You'll be able to fix it."

Alphys seems to calm down by Undyne's confidence, but she still looks really worried. "B-But I-. I don't k-know enough a-about human anatomy t-to help. O-Only h-humans could help him i-if my theory is right. T-That l-liquid is both d-determination and magic! I-If a human gets too much magic, I-... I have no i-idea what will happen! A-And I only have equipment for monsters, I've never examined a human before."

Undyne blinks slowly, all that science blabber going through one ear and out the other. But Buakuran being a human? Somehow… That doesn't surprise her. It's like she's known about it even if she's never heard it before. It's weird. But she quickly gets back her grin since a blank face only makes Alphys more nervous than before.

"So let's call some humans then! I mean, even if those cool anime things aren't real, they're still cool right? Byakuran should have some friends who are nerds like you are so they can help."

Alphys seems to think about this, looking down at the floor with small beads of sweat on her forehead. They could call some humans to help, but after all Byakuran has said about humanity… Is it really good for them to call them for help? They are monsters.

While Alphys is thinking about this, Undyne has already let go of her shoulders and is walking towards Byakuran. Alphys calls out that she should wait, but why should she? It would be good to call them now so they can get here while Byakuran does whatever he will do. Undyne see it as a great idea to call those humans now. So she stops in front of Byakuran, putting her fists on her hips with a serious glint in her eye. But the human just keeps on smiling.

"Ok, I'll leave on one condition." She starts off, narrowing her eyes a little more. Byakuran gets the feeling that refusing isn't an option… "When I get up to the surface, I'm going to call your human friends to come and get you. No objections."

Byakuran blinks a few times, his smile growing smaller in surprise. He himself have thought of that option, but he never thought anyone would actually want to do that task since everyone were so worried about his and Asriels health. This makes everything a lot easier.

"No objections from me." He says, smiling again at the fish woman. He starts to push himself up to his feet, feeling strong enough to stand again now that the new flames have settled in his core and the magic inside him is lessening. "I was actually about to ask if anyone could do that for me"

Byakuran puts a hand in his inner pocket and pulls out his phone. A flip up phone, he has always preferred the old fashioned phones over touchscreens. He opens it up, unlocking a small feature that will allow anyone who knows him to track his phone easier. Now, he's glad Shoichi installed that sender. Byakuran hands the phone over to Undyne with a smile, feeling safe that she knows how to handle a phone.

"Call the contact named Irie Shoichi. Or Sho-chan as I like to call him. He will see where the call is coming from just as long as you explain the situation." A new thought accurate to him and Byakuran turn towards the skeleton brothers. Both of them are talking to Frisk and trying to keep her awake. All of this is taking a lot longer than he thought it would. "Papyrus-kun, Sans-kun, Frisk-chan. Could you three follow Undyne to the surface? It would make my friends feel better if they saw humanoid monsters once they arrive."

Papyrus immediately brightens up at the thought of meeting Byakurans friends and straightens up slightly. He also makes invisible wind flap his cape and Frisk giggles softly from where they are still lying in his arms.

"OF COURSE! I, THE GREAT PAPYRUS, SHALL BE THE BEST OF HOSTS! I WILL SHOW THEM ALL THE GREAT PLACES HERE IN UNDERGROUND!"

Sans looks up at papyrus in amusement, putting his hands in the pockets of his hoodie. This is Byakurans way of getting the most innocent ones out of this, which is a great thing, but also making sure that his human friends can get as good first impression on monsters as possible. Also, that Sans is sent with them together with Undyne, it means Papyrus and Frisk are protected if something goes wrong. It's a great plan in Sans opinion, which he won't argue against.

"I don't think they're here to see underground, bro. they're coming to pick him up."

"OH, RIGHT." Papyrus says, frowning slightly at the thought of Byakuran leaving. The 'angel' couldn't have been here for more than two months, but it feels like they've known each other for much longer. But Papyrus soon brightens up again, the thought of never getting to see Byakuran again being pushed away from his mind. The 'angel' will surely find some way to stay in contact with someone as cool as himself. "THEN THAT IS AN EVEN BETTER REASON TO GIVE THEM A WARM WELCOME. IF WE HAD THE TIME, I WOULD HAVE MADE THEM SOME 'WELCOME SPAGHETTI' TO EAT!"

Sans chuckles slightly and starts walking towards the throne room, glancing quickly at Byakuran before looking ahead again. "I'm sure they would have loved it, bro. but we're kinda on a tight schedule."

Papyrus and Undyne follow after Sans towards the surface, the younger skeleton loudly talking about how he will introduce himself to the new humans and how he'll show them his puzzles if they have the time. It seems like Papyrus has forgotten why they are on a tight schedule, but the remaining monsters sure hasn't. Alphys steps forward, claws shaking as she looks up at Byakuran. If her theory is right, if he really used the whole syringe, then he will...

"B-Byakuran, are y-you really going to…?" She trails off when Byakuran gives her a bright smile. A smile so full of confidence and calm that she herself calms down slightly. How can he show that kind of smile but with a sense of acceptance around him? An acceptance like he understand that he might die. Or does he even know how dangerous that determination liquid really is?

"It's ok Alphys-chan. Even if I do die, I'll do it to save someone, right? That's what Yuni-chan would have wanted me to do if she were down here with me." He pats Alphys lightly on the head before he approaches the two older goat monsters. Both of them have conflicted looks on their faces, but they seem to have come to a decision. Whatever that decision is, Byakuran will still use Asriels soul to host Gaster in. If he doesn't, Gaster will just try to crack open his soul again instead of pushing the access magic out of his body.

"Toriel-chan, Asgore-kun. Have you come to a decision now?"

The two of them turn towards Byakuran, Asgore with a slight smile and Toriel with a pained look. The king nods for both of them and answers, Toriel is too conflicted at the moment to tell their decision out loud.

"To have our son back, it would be a dream come true. Just seeing him is amazing and if what you say is true, that he will disappear from our lives if he does not gain a soul, then both Tori and I will do anything in our power to help you."

Byakuran claps his hands happily, a bright smile on his face that he doesn't have to force this on them. It will make everything so much easier.

"That's great! Now, Asriel needs to sit down and I will just take a look at your soul." He looks briefly back towards Asriel, the goat child giving him a quick nod before sitting down against the pillar like Byakuran did a few minutes ago. Without waiting for any consent, Byakuran puts a hand to Asgores chest to see how his soul is built while still talking to everyone in the room. Asgore tenses up for a few seconds when he feels the foreign energy around his soul but soon relaxes.

"During this, you others can decide for yourself what you will do, but the most important thing is that I shouldn't be disturbed. I would recommend for you to not enter the surface yet, my friends could react violently to seeing monsters of such different form than humans. Hairy monsters and dinosaurs are usually the ones humans use in horror stories after all." He finishes with a chuckle. Once he has gotten enough information about Asgore's soul, he pulls away his hand and look between the three adults. All of them look very nervous now, all for different reasons. Byakuran needs to be certain that no one will interrupt him while he's fusing Gaster and Asriel together.

"If you choose to remain here, I have to remind you to not disturb me. If you try to stop me when I've started, I might accidentally kill him. He will scream, he will be in pain and this whole hallway will make it seem louder." He looks pointedly at Toriel when he says this last part, knowing that she's the one who needs it the most. "No matter how much he screams, I cannot stop. If you stop me, you will kill him."

Toriel looks down at the floor, her paws clenched tightly as she nods. Satisfied, Byakuran turns towards Asriel who's already trembling in fright. He isn't sure that he wants to do this anymore… The human crouches down in front of the child, releasing the restriction he has over his flames and making them easier to control. The protection around his core weakens as his wings emerge from his back with a bright light. The magic that was previously surrounding his body as it is pushed out is instead concentrated around his wings. The monsters stare in slight awe at the glowing angel wings, but Byakuran doesn't pay attention to any of that. His only attention is at the task he has set before him. He will get Gaster off his own back and fuse Asriels soul with Gasters magic. It will be a very delicate process.

The human puts his hands on either side of Asriel's face, making the child focus on him. This needs to be said now and not during the procedure. Or else, Asriel won't fully understand what he is supposed to do.

"Asriel-kun, I need you to listen very carefully to what I'm saying." Asriel nods slowly and gets a determined glint in his eyes. He will be able to do this! A smile twitches on Byakurans lips before he continues. "What I am going to do is drill a hole into your core. You will feel an enormous amount of pain, I can't help you with that, but i will do my best to make sure your body temperature doesn't rise. Once I have drilled a hole, I will guide the magic around us inside so it will fill your empty centre. That is how your soul can become whole. The most difficult part however, is that this magic has its own conscience." Byakurans eyes narrow when Asriel tenses up. The goat child is thinking about Chara, what they did to Frisk. "It's very, very important that you don't fight against it. This conscience won't do you any harm, but it will harm you if you fight this change. If you fight the conscience, you will fight off the second part of your soul. You will tear yourself apart. Work together, share your body, share your mind, become one person but still two different sides."

Asriel starts to cry, now feeling really worried about what is about to happen. He doesn't want to share his body, he wants to stay as Asriel. He just wants to stay with his parents. With a soft smile of his face, to try and calm him down, Byakuran wipes away the falling tears and ruffles the top of his head. If Asriel fights the change, Gaster will become enraged and attack Byakuran again. With magic still in his body and his core more exposed, cracking him open would become an easy feat.

"But you'll be able to do it. You're accepting at heart, and you'll still be part you. It's like when you absorbed the human soul, you both have control but still not."

Asriel calms down slightly, looking down at his own chest. Finding all of this very time consuming and kind of annoying, Byakuran puts a hand to Asriels chest and feels for his soul.

I have an idea…

Right after Gaster says that, Asriels soul slowly exits his body. An upside down empty heart, pulsing softly as it follows Byakurans hand. The human ignores the gasp from Toriel and immediately puts one hand around Asriel's soul while he positions one of his other hand's fingers in front of the heart. Asriel opens his mouth, to tell Byakuran to wait, that he isn't ready yet, but everything he can do once Byakurans burning finger touches his soul is to scream. Remembering how his parents are there, he quickly closes his mouth, biting his lip to stay strong for them while he's crying. But he can't hold on for very long, because he soon starts to whimper loudly as Byakuran drills further into his core. It feels like something is splitting him apart.

Byakuran is frowning as he continues to drill into Asriels soul, the magic around them moving in excitement. He can feel the strain on his core, how extremely fragile it is from breaking as he's putting all his concentration into keeping Asriels soul intact while still making a hole large enough for Gaster to enter through. If he didn't need his wings for further concentration, his core might not be as exposed as it is now. Apparently, Gaster notices when a small crack on Byakurans core grows and he starts to get worried. Byakuran is his ticket to being alive again, that won't happen if he dies while trying.

Byakuran, your core is cracking again. You need to slow down.

But Byakuran does the exact opposite, picking up his speed of the fire drill and making Asriel whimper louder. He completely ignores everything at that point, but he can't ignore Gaster. Gaster is literally speaking inside his mind.

If you continue like this, your soul will shatter before you even manage to make a hole! Your crack is growing!

"Then you do something about it… I'm busy…" Byakuran mutters back, almost flinching when he accidentally makes the drill too jagged and makes a small crack in Asriels soul. He quickly heals it with sun flames before he continues.

Gaster, not really knowing how he can help in his current state, wraps his magic around Byakurans core in hope that it will slow down the strain. That's when he notices the connection from the core to his wings. Maybe…

All of a sudden, Byakuran feels the protection around his core increase and the strain becomes a lot less. The control over his flames gets just a little bit worse, but it's just in time. Byakuran has managed to drill a small hole in Asriels soul using his flames, and now, Gaster can enter it. Releasing a slow breath, Byakuran slowly moves his flames to the side so Gaster can get in.

"Remember, slowly. Fill up the center with 2 millimeter distance between your magic and the cores sky flame."

Following Byakuran's quiet instructions, Gaster enters the soul, gently pushing aside the little wall of dying will flames Asriel already has and gather in the middle. As the soul is slowly filled up, Asriel's gaze gets more distant. But once the soul is completely filled like it should be and Byakuran closes up the hole with his version of sun flames, Asriel blinks a few times as his gaze steadily comes back to reality. Feeling absolutely exhausted by giving so much concentration to one task, Byakuran falls back on his butt with a deep tired sigh.

"There…" He says, falling to the floor on his back too simply because he feels like it. His wings are still out and annoying him, but that's a small price for relaxing completely. "It's done..."

Immediately after that is said, a sob of relief fills the corridor and he can feel movement over him. It must be Toriel and Asgore, because he can hear their relieved and happy voices speaking to Asriel, how much they love him and how happy he's alright. Byakuran smiles at having done something for someone other than him or Yuni. It makes him feel… nice. A weak pulse of energy comes from his wings, the extra protection around his soul drawing back. So that extra protection... He should have known. Byakuran can hear a pair of clawed feet approach him while the happy family reunion is still taking place and Byakuran opens his eyes to look up at a smiling Alphys. She seems happy too, but also in awe. She's the one who believed it would be impossible for him to create a soul.

"Y-You actually did it? Y-You-... c-created a soul?"

Byakuran laughs slightly, his own smile lighting up his face. He feels really good to have done this for Asriel, done this for all of monster kind. He never knew helping people could make him feel better. This must be why Tsunayoshi helps everyone he can. It's… It's nice.

"Yeah, I did. You shouldn't expect anything less from me Alphys-chan."

Alphys laughs softly, wiping away a tear that he didn't notice before. Monsters are such strange creatures, they are way too nice and care about others too fast. He and Frisk are the perfect examples.

Byakuran is brought out of his thoughts when a weight falls on top of his chest, making him lose his breath momentarily as he reflexively curls up and holds his hands over his chest. Which makes Byakuran hug Asriel who is right now lying on top of his chest. The goat child has a huge smile on his face with tears streaming down his face. When their eyes meet, Byakuran can see one of Asriels eyes shift from brown to light purple. Asriel doesn't feel as radiant when his eye changed colour, but he smiles all the same.

"Hey, Byakuran!" Someone shouts from down the hall, interrupting anything Asriel was about to say. The four monsters and one human turn in the direction of the throne room, seeing Undyne stand by the opening and shouting towards them. When everyone are looking at her, Undyne points towards the barrier with an excited look on her face.

"You didn't say humans could fly! They're already here!"

This makes Byakuran confused, are everyone flying? But only Tsunayoshi and himself should be able to fly, maybe Enma with his gravitation flames. Have time jumped forward while he has been stuck inside this loop? Byakuran really hopes it haven't been too long and that the contacts he had in the mafia are still there. With Asriel still on his chest, the human sits up and uses his arms as support.

"They flew here? In what way?"

Undynes eyes start to sparkle slightly, holding up a fist in excitement. They must have made a very impressive entrance to get Undyne this pumped up.

"They had flames on their boots! It was so cool! You have to come and see this Alphys!" Undyne points again towards the barrier before she runs off, way too excited over the humans to even see if they are following her. Once Undyne has disappeared, Byakuran gently pushes Asriel off his chest and quickly rise to his feet. He stands up a little too fast and gets dizzy, but he doesn't care about that. If they are all using flame boots, then they might have jumped further into the future than he thought. What about Yuni? Is Yuni ok? Will she still care about him? He waves away Toriels outstretched hand with a frown. Without taking any consideration to his own health, Byakuran uses his wings and flies to the end of the hallway and then flies through the throne room and to the barrier. He doesn't stop flying until he is at the end of the cave, sunlight shining through and blinding him. He can hear voices talking outside, both Undyne and Papyrus talking energetically but Byakuran can't place exactly who they're talking to.

Now, he's getting nervous. If time really has jumped forward, then he's been gone a lot longer than he would have liked. Did they even miss him? Is Yuni there with them? And his team, how have they been while he was gone? Have they kept up with the information work he started? Did they manage to expand their little organisation into a familia again? Byakuran almost doesn't want to know how much time has passed by, he almost doesn't want to meet them again and see their reactions. But he can't help but admit that he has missed them, hearing their voices. Perhaps they're acting odd like they used to be.

Byakuran takes a deep breath, straightening his back and puts a small smile on his face before he steps out into the sunlight. He can immediately see them, all of his friends. Vongola, Gilo Nero, his team. Not only that, but the kids, the 14 year olds he once knew, now look like adults. About the same age that he is. It's… strange. But they still act the same. The Vongola with their silly antics are happily talking with Papyrus, Frisk and Undyne, Gilo Nero and his team are staring at Sans since they are the more serious bunch. Byakurans smile only grows wider when he sees them. They are still the same.

Sans is the one closest to the exit so Byakuran walks up to the skeleton. With a soft laugh, he puts a hand on Sans shoulder and looks down at the skeleton first. He relishes in the stunned silence that appears when his friends see him. This might get more fun than he thought.

"Hmm, you seem a little rattled there, Sans-kun. Is everything alright?"

Sans grin widens and his previously tense posture relaxes. Now that Byakuran is here as evidence that they really do know him, the humans won't have any reason to attack a monster. Sans is just about to answer Byakuran on what's going on but someone interrupts.

"Byakuran!"

The human in question has just enough time to turn towards the voice and brace himself before Yuni throws her whole weight on him in a hug. Byakuran stumbles slightly, but quickly catches himself to hug the girl back. She is a lot older than when he last saw her. Well, the Yuni from that real timeline and not the Yuni from the future that is. Little Yuni was about the same age as Fran then, about 6 years old. Now, it looks like she's about 10. Maybe time haven't jumped forward as much as Byakuran thought. So Byakuran's smile widens into a grin as he adjusts his grip on her, spinning her around happily.

"Yuni-chan~! I've missed you! You've grown so much since I saw you!"

Byakuran blinks in surprise when he hears sniffles coming from the little girl and feels the shoulder on his vest getting wet. He looks confused at her before he looks over the rest of his friends. The majority of them have smirks and smiles on their faces, but the emotional ones, for example Bluebell and Ryohei, have tears in their eyes. He didn't even notice when Sans moved away from him together with Papyrus and Undyne and he clearly didn't notice when his friends walked closer to surround him.

Byakuran stumbles forward when Ryohei hits him in the back, he has gotten a lot stronger and the pat makes his back throb painfully.

"We're so glad you're ok, Byakuran! To the extreme!"

Byakuran gives Ryohei an awkward smile, well if they want to talk Japanese then he won't stop them. It's been awhile since he spoke in another language than English. Next, Byakuran has to lean back when Gamma gets too close to his face for comfort with a very angry look on his face.

"What were you thinking!? You've been gone for years and made the princess worried about you! What were you even doing in a mountain of all things!?"

Byakuran briefly glances towards Sans, seeing how the skeletons pupils are gone before he turns back to Gamma. Byakuran opens his mouth to answer when someone else interrupts him.

"That's right, that's right! You could at least have given a call, idiot Byakuran!" Bluebell says loudly, stepping forward to hit him in his side a few times before hugging him similarly like Yuni is doing, tears and all. Now, Byakuran is starting to regret his choice on meeting them. He really doesn't know what to do to calm down the crying girls. So he does the only thing he knows he can do, petting Bluebells hair.

"I was-" Byakuran starts off, but he's once again interrupted. This voice has a certain authority over it, and authority he never thought he would hear holding such confidence without the person being in their Hyper Dying Will mode.

"Alright, that's enough. Give him some space. Byakuran can tell us all about it once we're settled but right now, he needs rest." Gokudera is practically glowing as he nods and steps aside, everyone else doing the same. But Yuni and Bluebell doesn't let go of him as he turns towards Tsunayoshi. The new Vongola boss who seems to be a successful one judging from the others reactions. Tsunayoshi has a soft smile on his face as he steps up to Byakuran. It must have been a long time if Tsunayoshi not only managed to speak english before with Papyrus, but also perfect Italian. Reborn has done a great job.

Tsunayoshi extends a hand towards Byakuran, his smile growing into a grin.

"It's great to see you again, Byakuran."

Byakuran sets Yuni down on the floor, patting Bluebells hair before stepping up to Tsunayoshi in return. With an equally bright smile on his face, Byakuran clasps his hand with Tsunayoshi's, giving it a firm shake like he remember he did as a mafia boss in the future.

"I can say the same, Tsunayoshi-kun. It's great to be home."

OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

Aaand it's done folks! The official Underground plot is hereby finished! I still have loads of inspiration of scenes and stuff, so I'll most likely post an epilogue and some scenes after that. It was a lot of fun to write this fic and a new experience with the Third POV. I'm still trying to draw pictures, but inspiration isn't coming as easy as writing... But I'll do my best!

Sadly, I couldn't fit in that much interaction between the main KHR cast and Undertale characters, but I'll try to add more of that in the epilogue. There's still a lot of stuff I haven't explained, but that are all planned out. I love how Layered I made this fic. ^^

The epilogue isn't done yet, but I'll post it here once it is. Thank you for reading! See ya soon~!