Sans, had never done this before. He had never fused his Soul like that willingly. But he guess that this is an effect of the Glitch of the Timeline being buggy and all of that. Right now, he is in spirit form,

as his transparent silhouette is shown, along with Frisk, as they looked and see Asriel, the true form of Flowey, now as the so-called God of Hyperdeath, against Chara, his best friend and his brother, ever since Asriel he took him in, along with the other member of his family, his mother, Toriel, and his father, Asgore.

Asriel stepped forward, as he attempts to speak to Chara, his best friend.

"Chara, please we can-"

But Chara does not want to hear it, as he than spoke out.

"Shut up Asriel....You don't understand anything, don't you? Do you even know why all of this started?"

Sans, however, does, as he is well aware as to how this situation all started, as he than turns to Frisk, as his eye sockets glows blue, showing that, while they are now fighting Chara and are technically on the same side, this does not stop Sans from being angry at Frisk, who had caused the whole mess in the first place. And somehow, Sans is not the only monster of spirit form. Phantom Papyrus somehow appeared next to Sans and his own red eyes glowed, as he too stared angrily at Frisk, for all the stuff that he had done before. Frisk cannot help but look down in shame.

"That puny human you call 'friend'...Do you think I forced them to commit genocide? HA! Don't make me laugh"After doing the same 'pacifist' route over and over again, they eventually got bored...They did that on their own. The idiot just lacked the courage to finish at the very end. And only THEN I entered
They were the ones who killed everyone... by their own hand. I was just feeding from everyone's hate
If there's someone to blame here for everything... it's Frisk."

Frisk looked down in shame. He does not even attempt to argue at this sort of thing that Chara accused him of. As much as he would want to protest, he does not even try to justify it. In fact, in the way that Frisk sees it, Chara is right. And than, he hears Chara continue on with the explanation that he's saying to Asriel.

"Everyone portrays them as a pacifist child that wouldn't hurt a fly. But they are the ones who started the genocide. No one ever forced them to do it. I'm just trying to finish what they started...It makes me sick that they think that they're above consequences...That they can just toy around with everyone and get away with whatever they want...That's why all these weird events started to happen. They reset'd in a part where they weren't supposed to be able to. Creating all these 'errors'. And where do you think all that hate generated ended up? Right into me."

'So that is where all the hate came from.'

Sans thought to himself. It is due to the fact that Frisk is trying to defy the code of the entirety of existence, and through that, Frisk accidentally created Hate. And it seems that the Hate had affected Chara's mind.

"I'm not doing anything wrong. I'm just making sure that the little murderer you call friend pays for what they did. What are you gonna do anyways?
Frisk gave their soul when they were still alive didn't they?... Yet another glitch. I'm assuming you want to break the barrier at some point. But if you dare use their soul in order to do that.... They'll actually die
And won't ever be able to go back to their body...As a consequence from the glitch they caused... also
If you even think about reseting again, the timeline will just get even more corrupted erasing itself anyways."

Asriel looks down at his feet, deciding on what to think of next, as Chara than spoke out.

"But... this time, you can help me Asriel...My determination and power right now are bigger than ever... and I finally have enough to create this..."

A button than appeared, called Erase.

And needless to say, Sans recognized the button anywhere. He clenched his fist, as he felt his anger grow, and he began to wish that he can come out and fight against Chara, for making such a thing.

"This is... the only way to stop this, Asriel if we don't delete this timeline forever...That genocider will use all of your friends as toys forever. But we can end this here, right now...Sadly I can't press it... someone else is needed to trigger it."

But then, as soon as he finishes saying that, Asriel than looks up and spoke out.

"You said that he got us the same 'happy ending' multiple times...Something tells me, that at some point near the end I asked for forgiveness. And I'm completely sure that he forgave me for what I did...And just like me, he deserves a second chance."

This surprised Sans, and Frisk, as they did not expect such an answer to occur.

"You're an idiot Asriel... don't you see? You only have 2 options here ERASE or CONTINUE."

But Asriel than spoke back to Chara.

"Erase was never an option Chara."

He than raised his hand, and a warning symbol is present beneath the Button, and all of a sudden, just 2 second later, a Shocker Breaker appeared and shattered the button.

[There should be a GIF or video here. Update the app now to see it.]

Sans smiled, as he finally is filled with some hope in his eyes, that they can defeat Chara, along with Frisk smiling as well, as Asriel spoke out to him.

"So no, I WON'T accept your offer Chara. I forgive him."

Frisk was stunned, but at the same time, he felt a warming on his heart, as he felt like he should have some hope to stay alive and keep going. Sans does not know what to say, but if Asriel wants to forgive him for their actions, then Sans should just let it slide. Chara, however, seems to be eager to fight against Asriel, his brother and best friend, as he than spoke out to him.

"Very well... if this is what you desire. So be it."

Asriel looks ready, but he then looks down, as he touched something in his neck.

Inside of his neck is a heart locker, the one that Chara and Asriel had when they were young kids, back before they had died.

Accepting the challenge in the fight, he raised his right arm, and Shocker Breakers came down from the sky,

as Chara was able to dodge the last one in the nick of time. But Chara, not wanting be outdone, decides to fight back against Asriel. He used the purple slashes, than a red slash, and than finished it with yellow bullets.

But as that happened, Asriel blocked the purple slashes with Stars Blazing, used fire to counter the red slash, and then summoned his Chaos Sabers against the yellow blasts, the one swords that he had drawn when he was a kid.

Seeing the Chaos Saber made Chara still for a moment, before he reacted in a rage at the sight of it, while smiling all the way. He than turned his knife red and orange, just in case he tries to move out of the way, he slashed with 2 red slashes, before using one orange slash, as Chara then teleported right behind Asriel, who than blocked with his Chaos Sabers. But the red slashes hit him, and Chara used his yellow knife to blast him down. She than manipulate the orange slash to come and attack him. But Sans, in spirit form, briefly reappears, as he used his trident to swing it and used a purple slash to counter it, as Asriel fell down to a Star Blazing that he had summoned. He than swung his sword out of the smoke, as he than looked around and sees Chara behind him, firing yellow blasts of energy at Asriel, whine Asriel uses the Chaos Sabers in order to counter them. Chara and Asriel than engaged in a brief blade-on-blade combat against each other, until it got the point that Asriel uses his Shocker Breaker to destroy the Star Blazing, as Asriel than spoke out.

"Stop doing this Chara. I don't want to fight you."

But Chara than apppears in front of Asriel's face, as more and more of the Hate began to cover his body, except a small circle, as he spoke.

"Who are you again? Asking me not to fight? C'mon Asriel. Pretending that you didn't kill them all too? I barely recognize you."

Chara than disappeared, as Asriel than used his Chaos Buster.

He fired a bunch of bullets at Chara, but Chara than made a wall made of green magic in order to defend against it. Than, Char's began to teleport randomly, confusing Asriel, as Chara than sliced his knife at him, before sending him down to the ground, causing him agony with a cyan rope. Luckily, Asriel is unharmed, as he than looked behind him, and saw Chara doing that move again, involving the huge black mass, as he fired it down at Asriel. But Asriel has a trick up his sleeve.

Asriel than summoned a Hyper Goner in front of him, and this stunned Sans, as he did not expect for Asriel to make a weapon that resembles a Gaster Blaster. And than, as the Black Mass grew closer, it opened its mouth, as it sucked on the black mass.

'Jeez, this kid has a blaster that has an opposite funcition, suckling stuff if. But where is that black mass going to?'

As Sans said that, Asriel than noticed that Chara is not before him anymore, but Sans noticed it and spoke out.

"Kid, behind you."

Asriel turned and sees Chara inside of some sort of ball made of darkness. Than, the darkness gets added into the knife, as Chara than points his knife at Asriel, and spoke out.

"Welcome to my Special Hell."

Chara than swung his knife at Asriel, who was about to block it with his Shocker Breaker, but Sans than decided to take over in this moment, and used his Gaster Blasters to counter it, so that the Prince of Monsterkind than turns around to see Chara getting ready to strike him. But as that happened, Chara stopped, as he than saw something coming out of Asriel. The locket that Asriel kept, that symbolizes Chara and Asriel's friendship. But then, all of a sudden, the circle around Chara began to move, as it is revealed that it is none other than Chara's own locket, which is still kept intact, as Chara teleported backwards, and looked at it, with Asriel raising his arms, with Frisk and Sans appearing, as Sans spoke out.

"Kid, why aren't you-"

But as Sans began to speak out, Asriel than spoke out.

"Sans, Frisk...I'm sorry. I can't fight Chara. I can make him change his mind. He's in there somewhere... I can feel it. Otherwise, Chara'd have thrown the locket away..."

Sans looked at Asriel, wondering why he said that, as he simply spoke out to him.

"Kid..."

But Chara, looking at this locket, only ends up getting angry, as Chara than spoke out.

"Do you really think I'd care for such a stupid thing?"

Chara then teleports into the air, and ripped the locket out of his neck, as Chara than swung his knife at it whine throwing the locket into the air, destroying it, which stunned Asriel and made Sans made by the fact that he disregarded what Asriel had done for him.

"See Asriel? You really are a-"

But Chara said that, all of a sudden, a tear welled out leaked out of one of his eyes, stunning Chara and Asriel, as well as Sans, as he did not expect that.

But than, Asriel understood why this reaction took place, as he than spoke out.

"Sans...Frisk...We'll take the hate out from Chara. But we can't do it alone... we'll need help. Right now, the hate inside them is feeding off his determination. So we have to take care of that first."

Frisk nodded, as he than called out for help, as Sans does the same.

"Hey, if any of you kids can here us, we need you now. We need your help to save Chara from the hate that is consuming them."

Papyrus than spoke out.

"HURRY, MY HUMAN FRIENDS! THERE IS NOT A MOMENT TO WASTE HERE!"

Chara got mad, due to the fact that he is being reminded of who he once was, back as his weaker self, as he than spoke out, almost like he is about to lose his mind, as he speaks to no one in particular.

"I don't need anyone now. ANYONE!"

He than swiped out and attacked with a red slash, as Asriel did not look. But than, the Green Soul of Kindness appeared, and protected Asriel.

The Soul of Kindness than used his pan to make a shield with the Detarune symbol, as he than took on the form of a green ball of energy, around Asriel's hand. Asriel, without any hesitation, threw the ball, as Chara got close, striking her across the chest. Than, Perseverance came next,

We Asriel does the same thing, and attacks Chara with it. And when those 2 attacks happened, Chara began to have 2 flashbacks, which is about the time when he first met Asriel, and how thankful and happy he was that someone decided to take him in. Needless to say, Chara does not like this, as he than shouted out.

"STOP IT!!"

But Asriel does not stop, as he summoned Justice to aid him, as Justice fired her gun and was able to stop the attack that Chara tried to use on him.

Justice turned into a ball around Asriel's hand, as Asriel fired it into Chara's chest, forcing him to remember the fun times he has with him when they were kids.

As Chara stepped back, they looked stunned, as 3 more appeared, Integrity, Bravery, and Patience.

As soon as they appeared, Asriel fired them at Chara, all 3 of them at once. Chara tried to stop them, but when he did, Bravery blocked his attack, after Patience went inside of Chara first, then Integrity went inside of Chara next, and then, Bravery was able to get inside of Chara, and it is at this moment thar Chars began to feel his powers weakening, he does it understand why. This is now how this fight was supposed to be. It's supposed to be in his favor, his!

And than, Frisk appeared, along with Sans and Phantom Papyrus around Asriel. They both held their souls into the air, Frisk on his left hand, Sans on his right hand, and Phantom Papyrus between both of his hands, as Asriel draws upon their Determination. This one will be more stronger than ever, even when compared to a single Determination Soul of being drawn upon, by 3 times the amount of energy. The moment that happened, Asriel fired it at Chara, who had began to bleed from both of his eyes and his mouth, and when that happened, a bit of Chara's hate was removed from his left cheek, instantly. The moment that happened, Asriel changed back into his normal form, back before he died. And he has a sad look on his face.

[There should be a GIF or video here. Update the app now to see it.]

"Chara, please... I know you're in there."

But Chara laughs as if it is funny, as he spoke out.

What are you talking about? This is who I am I'm here to make sure that the timeline gets erased, as it was supposed to be.

But Asriel spoke back to him.

"You're wrong..."

Chara, clearly not understanding what he is talking about, began to speak out to Asriel.

"HA! How would you know anything about m-"

But than, Asriel began to speak out.

"You like chocolate... and drawing...And playing with toys and mom's butterscotch pie...And certainly... you wanted to save monsters."

Chara snarled, as the Hate began to consume Chara's left cheek again.

"Get away from me..."

But Asriel continued on.

"You wanted to free everyone, because you care about them all."

Chara than shouted out to Asriel.

"NO!!!!"

But Asriel than shouted back, which stunned Chara, not expecting that sort of reaction.

"STOP PRETENDING LIKE YOU DON'T CARE!!!"

But Asriel than calmed down, but he felt a limp swell in his throat, as he than spoke out.

"I know you Chara...because..."

But Chara did not want to hear it. He raised his knife into the air, and prepares to strike down on Asriel, when Asriel came forward, lunged and Chara, and hugged him, and it is something that he is stunned about, and yet, there is something familiar about this hug. And than, Asriel finally spoke out.

"I care about you more that anybody else. We're best friends after all aren't we?"

And at that moment, Chara felt something breaking. The Hatred, it is coming off of him, as he than broke free, and hugged Asriel.

His brown eyes having finally returned to normal, along with his face, as he than spoke out.

"I'm sorry Asriel..."

But Asriel than simply spoke back to him.

"It's okay Chara, everything will be ok now. I'll never leave you again ok?... we'll be together forever."

Chara smiled, as tears welled into his eyes, as he than spoke out.

"I'd...love that."

Asriel than continued to speak.

"I don't care if the barrier is broken... as long as I can be by your side."

Chara smiled, but than, he felt something, a crack. Chara's leg, it is starting to break apart, no, all of Chara is breaking apart.

"...Asriel. I wish we could've spent more time together."

This made Asriel confused, as he than spoke out.

"Chara...what do you mean..."

Chara than spoke out.

"The only thing keeping me in this world was my determination..."

He than teleported in front of Asriel, as is now no longer within arms reach.

"but now that is gone, I..."

Asriel, realizing what is happening, spoke out his name.

"CHARA!!!"

But Chara did not seem to mind, as he than spoke out.

"Although... I'll be able to give you something before I leave."

Asriel, with fear in his eyes, as well as sadness, spoke out to Chara.

"Chara... d-don't leave."

But Chara did not stop speaking, as he than continued.

"You've gathered different traits through our battle haven't you?... however you don't have a vessel for them."

Asriel shouted in our grief at the realization of what will happen next.

"Chara, don't disappear!"

But Chara, knowing of his face, sends one last gift to him.

"And what's left of my soul, is the perfect vessel for you..."

Asriel, crying hysterically in grief, runs up to him in order to try and grab him.

"Take me with you! Don't leave please!"

Chara smiled, a tear leaked out, as Chara spoke out.

"Heh...You always were a crybaby..."

Before Asriel can grab him, Chara shattered completely, his empty soul remains, as all 7 traits then entered the empty soul of what was once Chara's now belonging to Asriel's.

When the flash of light was gone...all that is left, is a rainbow soul. Sans is back in a physicial form, his determined monster soul back with him, as the Phantom Papyrus is next to him, floating next to Sans, as he felt very sad for the fact that the young prince lost his friend.

"Sans...Frisk...Thanks... for everything...I won't need your soul to break the barrier now, you'll be able to go back to your body."

As soon as he said that, he lends Frisk his soul back, as Frisk reabsorbed it back into himself, as Asriel continued.

"And you got back your control over the timeline."

Asriel looked down at his his own soul, his new rainbow soul, as he than spoke out.

"Now...Let's do this..."

He closed his eyes, and focused onto the power of the Rainbow Soul, as he than used it, to finally break the barrier, now freeing all of Monsterkind, permanently. And now with 2 new guests. As the dome of Hatred was gone, Asriel, Frisk, and Sans appeared, unharmed, everyone waiting for them. When Asgore and Toriel saw Asriel, they hugged him, tears of joy streaming down both their faces. Sans was crushed into a bone-breaking hug of his still-alive Papyrus, who was happy to see that Sans is still well and alive. Gaster was present, happy to see both of his sons together.

After that, everyone looked up at the son, with Gaster looking and feeling at it was well, the feeling that he had not forgotten, and now revisits it.

"THE SUN FEELS SO GOOD!"

Phantom Papyrus said, as Sans nodded his head. Than, Phantom Papyrus spoke out.

"WHAT DO WE DO WITH THE HUMAN, BROTHER?"

Sans than turns around to look at Frisk, staring happily. But Sans was not happy, as he needs to get something off of his chest.

"Hey kid, care to chat a bit?"

A minute later, Sans and Frisk began to speak privately to one another.

"So uh... I'll get straight to the point. Because of one of these 'errors', I can remember everything from these past timelines...Even the hundreds of the ones where you killed everyone...Right now... we have yet another 'good ending' this one is... quite unique, but uh"

Sans looks down for a little bit, choosing his words carefully with what he'll say next, as he than spoke out to Frisk.

"Be honest with me kid, when are ya gonna reset?"

Frisk than began to speak out.

"I promise I won't-"

But Sans was not happy, as he than spoke out again, his left eye flaring purple and right eye red again.

"I said 'be honest', I did not say promise."

Frisk looked down a little bit, as Sans than calmed down for a little bit, as he than spoke out again.

"Look... if you got bored enough to do 'that' then...
I don't really have any guarantees that you won't reset this time do I?"

Frisk looked down, as Sans walked away.

"Just, let me know when, 'kay?"

Sans walked away, with Frisk looking down, thinking of what to do next.

Inside of a room, Sans is looking into Frisk's open door, with Frisk seeing the Continue or RESET Button, as Frisk raised his hand into the air, and prepares to bring it down, with Sans thinking to himself.

'Here we go again.'

[There should be a GIF or video here. Update the app now to see it.]

But than, something shocking happened. A crash was heard, like the sound of when glass breaks when impacting ground, as Sans snapped his sockets wide, and saw the RESET Button broken to pieces, by Frisk's own fist, as Frisk than spoke out to Sans.

"I won't reset again...From now on, I just want to CONTINUE."

This stunned Sans, and Phantom Papyrus looked as shocked, as he than spoke out.

"MY, MY...FRISK HAS CHANGED FOR GOOD AFTER ALL."

And Sans smiled genuinely, as he spoke out to Frisk.

"Heheh...guess you're a good kid after all."

One day later...

Sans is shown to be walking all on his own, as he looked around the place that he is in. He is near Mount Ebott, as he looked at his former home, now having gained a new home. Sans sighed, as he smiled at this, as he spoke out to himself.

"Well, I guess I got a nice home."

Sans began to walk away...but then...he sensed something. He looked up, and saw a black mass coming down to him. It was HATE. Sans moved out of the way, as he began to fight it. He launched tridents at Hate, but it avoided its attack, and before Sans knew it, it latched onto his arm, and began to try and enter his body, as it pierced his Monster Determination Soul by using a tendril to pierce his soul. Sans could feel himself losing control, as something is being filled inside of him, the Hate that the black mass is made from. However, he was able to summon his trident and sliced the tendrils off, before launching fireballs at the large mass of Hate, forcing it to leave Sans be, and to not com back for him again. Sans held his chest, and felt his soul thumping, as be spoke out to himself, a tone of pure stress inside of his voice.

"What...what was that?"

Sans breathed, as he has no idea what had just happened, as Phantom Papyrus spoke out to Sans.

"BROTHER! ARE YOU OKAY?!"

Sans looked at the Phantom Papyrus and nodded his head, as to not worry him.

"Yeah, I'm okay, Paps. Don't worry."

Sans said, as he than began to walk away. But unbeknownst to Sans, a black liquid began to go down his left eye socket, as he walked back home, clearly unaware of the condition that he is in.