I hope you enjoy this fight. It's gonna be a real interesting fight. But first, a review.

Treefrogger: I won't, I just couldn't resist when I thought of the Yangs taking the "Go fuck yourself" phrase too far and it evolved from there. Trust me it's gonna get better from here sex joke wise.

Alright I hope you enjoy. Please leave a Review, Favorite, and Follow if you wish.

All Sans's and Papyrus's in-game lines are edited versions of the original dialogue from the Undertale Wikia.

Also fight scenes get music. You can play a remix or the original if you wish to know the songs that come to mind when I wrote these fights.

It was the next day on Saturday, as Team RWBY and the Future Stepsisters stepped into the familiar combat arena, they noticed Ozpin, Gylnda, Summer, and Qrow all watching them as Team JNPR arrives a few minutes later.

"Hey, your the guy I ran into yesterday!" Jaune said as he recognized the hoodie before seeing her face. "There's T-t-two T-Ya-Yangs...?" Jaune asked as he fainted. Nora then looked at Ren "Called it!" Much to the confusion of everyone except Team JNPR. Pyrrha just sighed at the antics of the two as she noticed the two future stepsisters look at her like she died, much to her confusion.

Ren sighed and looked at them "Nora was listing the possibly of the secret you guys were gonna us today all night. Yang and Ruby's future selves happened to be a guess."

"That guess was oddly specific and correct." Blake said in shock at Nora being right.

"So sis, I take on Team RWBY and you get JNPR?" S!Yang asked her sister once they snapped back who nodded.

After the J of Team JNPR woke up. They stood on the sidelines with P!Ruby with Team RWBY standing on one side of the arena, and S!Yang stood on the other.

Summer pulled out her scroll, which was far more advanced than the current scrolls at this point, and was sending Alphys live footage.

"It's a beautiful day outside. Birds are singing, flowers are blooming... on days like these, kids like you..." S!Yang began, her voice now sounded like a mix between calm and cocky.

As the battle began as S!Yang held up a hand as she slammed it down. Causing the SOULs of Team RWBY to feel weight on them as they mysteriously turned blue.

Sudden a barrage of bones flew at them as they tried their best to dodge, but noticed the bones that hit them go right through them. Yet, they felt their aura drain without even activating it before seeing what seemed to be giant Beowolf's skull, minus the colors and eyes as it had two white pupils that faded and turned into one glowing eye as it opened it's mouth and a laser fired from it much to the Teams horror as they ran in separate directions to avoid the blast.

"Anyway, as I was saying, it's a nice day out. Why not relax and take a load off?" S!Yang suggested. She noticed each member of Team RWBY had taken a bit of damage from her first attack.

(Cue Undertale: Song that might play when you fight Sans)

Everyone present had mixed reactions to said attack.

Ruby was wondering where Yang had gotten this power and how she did all that.

Weiss was wondering how strong she is compared to Yang.

Blake was wondering how many bones did Yang have?

Yang was feeling a mixture of pride that she was strong, yet confused at what just happened.

P!Ruby knew that this was gonna be fun to watch and smirked as she gave a thumbs up to her sister.

Summer was the same as P!Ruby only she clapped instead of giving a thumbs up.

Qrow then began to wonder if he was drunk and what was in his breakfast.

Glynda was shocked at such power and knew Ironwood would take interest in this situation if he caught wind of it and try to make his soldiers as strong as S!Yang.

Ozpin stared at Yang with shock that said 'could she be a maiden?'

S!Yang then smirked as Ruby predictably rushed at her and swung her scythe, only to hit nothing as S!Yang sidestepped it with minimal ease,

"What? You think i'm just gonna stand there and take it?" S!Yang asked, winking and shrugging with that smirk.

Ruby was surprised, she was surprised that this Other Yang moved at a speed faster than her semblance could allow her to move. "...Yes...?"

Weiss however then ricocheted off her glyphs at S!Yang and attacked as the blonde ex-monster simply dodged the attacks with minimal ease surprising the heiress.

"Woah Ice Queen! No need to give me the cold shoulder. I'm not ready for the chilling embrace of death yet, and dodging your attacks is snow problem for me." She joked. Much to Weiss's annoyance.

"Good one me." Yang shouted to her older self. S!Yang smiled and bowed as she dodged a back attack from Weiss who landed with her teammates.

Suddenly various blasts of energy from multiple Gaster Blasters that S!Yang summoned flew at the team as they managed to dodge most of them, leaving them at around half of their aura left.

Yang rushed at the other Yang so she couldn't summon any more Blasters or Bones. But suddenly flew up as S!Yang threw her right arm up. She had a blue aura around her.

"What's wrong? You're looking a little blue." S!Yang said jokingly. Both Yangs then stopped and laughed for a few seconds before S!Yang threw Yang around and into walls. Yang then summoned a large amount of bones with a few cyan blue ones. Suddenly the bones rushed at them as they pelted Team RWBY and in a matter of seconds, their aura was drained completely.

(Stop Music)

"...and game, set, match." S!Yang said with a victory pose.

Team RWBY then fainted due to aura exhaustion as our hoodie wearing hero went to Summer and saw that the livestream battle had gotten the following comments on the UnderNet.

ALPHYS: That was great Yang, good job on the win. I could do without the puns though. DX

StrongFish91: Sans that was awesome, like an anime fight done right! I wanna spar with you sometime. Where did you learn such power lazybones? XD

MountainMonsterKing99: Sans/Yang, those moves of yours were flawless. I can see Doctor S. Rose has taught you well.

GoatMomT: Yang/Sans, while I don't approve of the fight, I admit your skills were very tactical. You made a good use of your powers and speed to hold your own. You didn't even need your weapons or semblance to win. Also Alphys informed us about aura and semblances. I am surprised Frisk hasn't unlocked their semblance or made a weapon yet. I hope to have a pun war with you soon.

FriskyUndergroundChild: *The sight of a great brawl has filled me with DETIRMINATION.

Yang snorted at Frisk's Undernet name with a "Wow kid, great choice of name there." Lucky kid to get away with it and not have Tori catch on. Speaking of which, he'd love to have a pun war with her sometime.

After taking Team RWBY to the recovery room so they can rest. Summer then prepared to livestream the second of two great battles.

Team JNPR vs P!Ruby.

When they got to their sides. The battle began as Jaune hoped that they won't have as bad of a time as Team RWBY did with S!Yang.

(Cue Undertale: Nyeh Heh Heh!)

Ruby then summoned a couple bones forth as they rushed at Jaune who tried blocking with a shield and using aura. It didn't work, but unlike S!Yang's bones, P!Ruby's vanished upon contact and only took a small part of Jaune's aura down. The others just dodged after seeing what happened to Jaune.

Pyrrha rushed forward and then slashed P!Ruby who took only a little damage from the attack.

"So you're all serious... then, let's see if you can handle my fabled "Blue Attack!" P!Ruby shouted.

Out of nowhere, a single blue bone went slowly at them as Jaune was dumb enough to try and block it again.

Suddenly he turned blue and took no damage and felt weighed down as he saw his teammates also turn blue as they were confused.

A barrage of bones rushed at them as he felt he should try jumping over them, only to find him jump like he was on the moon. He was successful, unlike his teammates who got hit and saw they were somehow locked to side to side movement.

"You're blue now. That's my attack! NYEH HEH HEH HEH HEH HEH HEH HEH HEH!" She cackled playfully as the battle began for real.

(Cue Undertale: Bonetrousle)

She was done doing her battle like before and mixed things up as Orange and Blue bones suddenly rushed at them. Nora then held still as she didn't feel a thing before realizing something. In an act of courage, she rushed though the orange bones without stopping as P!Ruby looked surprised before grinning.

"So it seems like Nora finally gets the act of PATIENCE and BRAVERY." She said as the others caught on to what our red and black haired hero's colored attacks evasion tricks.

'So blue attacks can be dodged by not moving at all, and orange attacks can be dodged by keeping movement...' Ozpin realized as the others that weren't familiar with it are now grasping the concept.

With that, Nora managed to get a direct hit on P!Ruby, hitting her in the stomach as it let some air out of her but it was't anything critical thanks to her aura.

"Well, it appears I'm gonna have to step it up a bit then." P!Ruby said before throwing wave after wave of bones in random patterns as it kept hitting them and taking their aura down a lot, just getting under one quarter of it.

"Woo! Go Sis!" S!Yang cheered as Team JNPR was on their last leg as Ren rushed forwards and opened fire on the silver eyed warrior.

P!Ruby, tired of taking damage, summons a bunch of blue bones to destroy the speeding bullets before throwing them at the black and pink haired fighter.

She then pulled out her Crescent Rose and put it into sniper mode.

Since they fought Ruby in combat classes before, they knew what the sniper could do, but didn't expect what happened next.

It began to rapidly fire white, blue and orange bullets in a wavy pattern.

They tried to dodge it, but couldn't predict where the orange parts were so they stuck dodging her wave of bullets until she stopped a minute later.

Swapping it into it scythe mode, Ruby slashed with a white wave of energy trailing the blade.

Jaune tried to clash with it, but found it was gonna break his sword if he didn't do anything soon so he jumped back.

P!Ruby then used her speed semblance to suddenly get behind Jaune and knock him out in one slash.

She then did the same for the others.

(Stop Music)

"And the winner of this bout is me." P!Ruby said as her cloak flowed in the wind as she smiled.

"I guess from the start, we knew they were..." S!Yang started.

"Don't you dare!" P!Ruby glared at her. But the glare only looked adorable on her.

"...boned." The blonde jokester finished with a wink and a shrug as a rimshot played from Oum knows where.

P!Ruby then screamed.

"C'mon, you're smiling." S!Yang pointed out.

"I am and I hate it." P!Ruby admitted.

They then looked up and saw Ozpin and the others have shocked looks as Summer nodded proudly.

"Too much?"

"PSSH, more like not enough in my opinion."

They then looked at the Stream commenters.

ALPHYS: Well done Ruby, I can see you're gonna be a really powerful huntress one day.

StrongFish91: Wow, Papyrus. I didn't expect such skill. I take back all thoughts that you're too innocent and nice. You can be a real pain in the tail with that power. Let's spar together one day. I also guess the narcissism was part of the act?

MountainMonsterKing99: Papyrus/Ruby, I was very surprised when you began to slash them, reminding me of my trident.

GoatMomT: Ruby/Papyrus, I can't believe that your power, while tame compared to your sisters, far exceeds that of mine.

FriskyUndergroundChild: *The familiar moveset that you've seen before fills you with DETIRMINATION!

"*Gasps* I am honored by these genuine complements!" Ruby said in fake narcissism thanks to her experience as Papyrus as reminded of her by Undyne.

Ozpin then began to ask "Who are these people that are commenting and what is 'UnderNet' exactly?"

"Our Boss Monster friends and a human girl that prefers to go by nonbinary terms and is verbally mute that fell down and broke the barrier named Frisk." S!Yang explained as Team JNPR also was taken to the recovery room.

"How old are they?" Ozpin asked.

"I don't know, I never really though about it." S!Yang guessed.

"Where are they now?"

"The mountain that you sent Uncle Qrow to." P!Ruby said.

"I can get us there in a flash if you want. I know a shortcut." the blonde boxer said.

"Alright then. In the meantime Glynda, you're in charge until I get back."

With that... the three walked out of the room and were gone without a trace.

I hoped you enjoyed these fight sequences. While they are OP, they are pretty tame by Saitama standards.

Also if you're curious as to how Summer, Yang, and Ruby treat their powers allow me to sum it up.

Yang is a master of the telekinetic Blue SOUL mode, is second place when it comes to the Gaster Blasters, and can only use blue attacks when it comes to her colored attacks.

Ruby is the best when it comes to colored attacks as she's mastered both Orange and Blue, her skill with the Gaster Blasters is lacking, she is also only mediocre when it comes to Blue SOUL mode.

Finally, Summer is a genius with her Gaster Blasters for obvious reasons, she also can't use colored attacks, and is the least skilled with Blue SOUL Mode.

If you have any questions or comments leave a review. Also why don't you Favorite, and Follow while you're at it. You can also private message me if you want and I'll try to get back to you as soon as I can.

If you want any lemons containing our heroes, Sans!Yang and Papyrus!Ruby please let me know and I may do a separate fic on lemons so that way people can skip out on something that is not 100% required.

Also, how old do you think Frisk should be in this fic. 10, 15, or 18. I never really did give an age for her, yes Frisk is female but often goes by nonbinary terms like 'They' and is mute. This was inspired by the PTA Sans fics and comics I've seen.

Speaking of separate fics, I may do a RWBY Chibi fic that will be T Rated for light swearing, some sex jokes, and for Qrow. What do you think about this? I've seen some fics get RWBY Chibi counterparts so why not this one?