Call of the Void

Click..click..click. The sound of a clock played within the void despite its absence, the noise echoing throughout it as a sense of anticipation would brew between both of the groups, each ready and eager to engage in the duel to show off and test their might, although for Gaster it was more so testing the might of his sons rather than himself, he already perceived himself to be the superior to them, this is a chance to show themselves.

DING

The nonexistent clock decided to ring and thus it would represent the beginning of a battle between kin. Gaster stood off by himself, his hands held behind his back, he made no motion after the ding had sounded, he was prepared for them to come towards him, besides.. he wasn't the challenger in this situation.

Gaster would be in for a surprise as the both of them charged right towards him, this made Gaster raise a slight eyebrow as he expected for both of them to act smarter than this, and it would put him on slight edge as anticipation came over him for any of their moves.

Papyrus and Sans were currently running at Gaster and when the distance between them had enclosed at almost the optimal range for combat, something had happened. Papyrus had suddenly been flung forward with additional speed far surpassing the one that he was moving at. Gaster opened his eyes wide in shock at the sudden speed, but manifesting the power of kindness from his repository he created a barrier to defend himself and braced for the attack just in time.

When Gaster opened his eyes again he noticed something, his barrier wasn't even hit, whatever Papyrus had done did not seem to be directed at him, but he did see there was a bone stuck down in the ground in front of him. And he could hardly see with all the strange fog that pervaded around the area. Something causing even more alarm was that when at his level of soul sensing neither of their presences could be felt to him.

Just when he thought he had lost them, he heard the iconic noise of the growl of a Gaster Blaster as it charged up, his eyes darted towards the source in an instant with his barrier temporarily dropping. He outstretched a hand towards the house and shot a blast of void energy that disintegrated the blaster 

"Hmm clever, but not clever enough. I expect more from you two-" Gaster was speaking until he suddenly got cut off as a large explosion happened right behind him, and his mind suddenly raced as he knew what it came from. The bone! Papyrus somehow found a way to make it explode? That is impressive, but not enough.

"No more games!"

Gaster gave off a terse shout while still mostly keeping his demeanor wiping off the flames that sprouted onto him with a burst of darkness. This spreading out encompassing the whole expanse blasting back Sans and Papyrus both revealing their locations to him now.

===========

Papyrus and Sans both had blemishes on their clothing and were wiping them away. Now staring down Gaster with a new turn of the battle being set. Papyrus would give a concerned look towards Sans now before speaking as he had a query for him 

"Brother, you got any more bright plans. I'm still concocting one in my head.. Yes brother, I too can craft! I'm already setting up my traps."

Sans would chuckle at his brother and he seemed quite proud, he still remembered when he was a wee little lad or even back in the underground he wouldn't be able to handle himself this well, but here they are.

"Ah don't worry bro I got a plan." He would tap the side of his skull as a lightbulb appeared over his head. Sans then whispered something quietly towards Papyrus that made his eyes suddenly explode wide open.

Papyrus would let out an exasperated sigh for a moment and then spoke. "Alright alright, I guess if we have to."

Papyrus would do a weak bone toss towards Gaster. Gaster would look down at the bone with confusion and then look right back up to Papyrus, he felt like laughing. Were they throwing in the towel already?

Papyrus would suddenly let out a ravenous shout of words with power lacing them. And made a declaration.. "With this bone I summon, ANNOYING DOG!"

Gaster would be off put, how could the dog even get here and what would it even do. Within the next moment the entire void would shake, and from the bottom a crack formed in it and a dog came out of it suddenly jumping right into the jaw of Gaster with the bone now in its mouth

"Ruff Ruff!"

The dog only barked right after which annoyed Gaster with its piercing loud noise and he had now been knocked over. And at the same time that he had been plenty of Gaster Blasters surrounded him within the sky. And then with a snap sans released them and created an explosion with the forceful size of a mountain. Unlike his usual blasts it would linger to do more damage. While this was going on he covered Papyrus in blue magic and caused it to push the explosion away from his body acting as a barrier.

Papyrus ran forwards with a white bone and soon found Gaster in the blast, he seemed pretty much unaffected by the actual force of the blast; it was just slightly pinning him down as he tried to stand up. When he did stand up he saw Papyrus with the bone. Gaster made a swift movement and slapped the bone away from Papyrus, or so he thought. Papyrus turned the bone into blue midway and cause Gaster's hand to get stuck in the bone and suddenly cause immense damage as he took it out of the bone. Gaster held his hand for a moment, and suddenly received an uppercut from Papyrus sending him up into the air, at the same time the blasts of Sans suddenly ended. 

Gaster had his body and soul turn blue as he saw Sans holding him still within the air with him struggling to try and resist it. Although he was suddenly stabbed with various other blue bones coming from Papyrus. After he had done so Sans slammed down Gaster into the ground and right back up to where he was. Gaster had finally shown slight signs of being damaged. He closed his eyes as if he had been knocked unconscious…

When Gaster opened his eyes once more a red glow had shined from them, he was filled with a certain brimming emotion. That was determination, he had somewhat gauged the current level of his sons and now he was going to go far harder on them knowing what exactly they could handle. He suddenly had a burst of red energy shoot out from him along with the essence of the other souls as he broke free from the blue magic?! He had somehow done a feat that should usually be impossible for anyone, but he had destroyed its very effect on his being.

Gaster contorted the void and tentacles arose from it and slapped away both of the skeleton boys and actually caused a decent amount of damage to them once more, Gaster really putting them on the edge. Papyrus still seemed quite up and at 'em, but Sans was not as durable as his brother and the powerful strikes from Gaster now had a semi toll on him.

Sans stood ready with his brother despite this, but Papyrus put a hand up behind himself in front of Sans motioning for him to stop.

"Sans stay back brother, I see your wounds, no purpose to get hurt more. Besides I have one more idea in my skull and i'm gonna need to ready for it, just try not to get hit" Papyrus would yell out before charging forward once more towards Gaster, but this time he was riding on a bone like a hoverboard which was covered in orange magic making him go incredibly fast.

On Papyrus's way Gaster did not hold back a thing, the void warped itself to the whims of Gaster distorting reality to suddenly become inverse for Papyrus and making all of his directions… opposite. It's hard to actually explain for anyone, but what they intend to do with their body the opposite of it happens. Papyrus suddenly launches gimme backwards not realizing what exactly is going on.

As Papyrus bounced around in the air trying to adjust to this new sense of reality, Gaster lamented several more attacks onto Papyrus consisting of spawning various spikes within the void out of its pure black ebony essence. These spikes came from all around it and shot like a bullet directly towards Papyrus. Yet he would not have it simply end there, he summoned his own humongous Gaster Blaster releasing its ethereal blast upon Papyrus…

Papyrus had managed for the most part to actually avoid the spikes only getting grazed by a few, it being from either from dumb luck or the incredible adaptability of Papyrus, nonetheless soon after he got his bearings and turned towards Gaster with a glint of determination in his eye as he rocketed forwards, he was an anomaly. The more he was getting hurt the stronger he was becoming!

Gaster intended to soon end the fight before he could become much more of a problem as he noticed this very fact, the blast of the gigantic ancient magic being released upon Papyrus. Papyrus suddenly braced for impact as rows of bones appeared in front of him, they started to crack with an utmost ease spelling out his doom, that being until Sans sprung back into action to assist his brother, he had just drank some ketchup so he was back in a more normal state once more. Sans unleashed a powerful triple blaster to clash with the opposing blast of Gaster.

"Hey guess what old man, together me and my bro are unstoppable ya hear that. Doesn't matter how strong you are." Sans spoke and then winked and shrugged, he showed off his certain jocular attitude that could sometimes make people rather aggravated with him, but for once in his life, he was serious about this.

"Thank you… brother." Papyrus said with a big grin coming onto his face as his bones crackle with life, and a strange energy seems to spark within him. "And now.. for this"

Papyrus suddenly moves out of the way now that he is free to and floats higher up in the air. He raises up his hand… revealing the setup trap that he had made. Suddenly magic had made itself visible, blue bones suddenly became stuck within every part of Gaster's body, one move could be deadly.

"You see father, when you first got hit by my bone explosion, it wasn't to hurt you, but it was to place my magical energy on you."

Gaster couldn't believe it, Papyrus could really think that far and so advanced.. he had underestimated him. Using lingering magic to fuel another spell was not a move he had thought of, but now one he would experience first hand. Yet he had a feeling there was more.

"How impressive my son, but let's see if you can follow through."

Papyrus lowered his hand and from the ceiling thousands upon thousands of titanically sized bones had appeared, these bones splitting into various extremely tiny ones. Papyrus launched them within an instant down upon Gaster in an area of affect motion. "The Coolest Rain." This was the name that Papyrus had decided to adorn to his grandiose technique.

Gaster, seeing what would come next, quickly shifted through his mind and thought of a way to escape by simply using his location shifting magic, but then he recalled that it wouldn't work with their now advanced blue bones.. Ah he could simply destroy them with a bravery explosion. And just as Gaster charged it up from his body it suddenly stopped. He looked around wondering how exactly only to find Sans extending his hand. There was a blue flame extending from it… Gaster made a quick deduction. He was using the blue magic on his very abilities to stop them from being used, how clever.

"Sorry pops, better slow your roll there and let this happen." Sans would mock him seemingly once morel

"And this is what we call, the ultimate bro combo!" Papyrus would say right after, was there still something more?!

Gaster is now riddled with various bones across his body from the rain, although most of them bounced right off of him. Now he looked at his two sons who stood side by side, Sans seemed to be glowing a bright blue, and Papyrus an orange.

Sans spins a finger around in the air as a spherical sapphire vortex appears in front of himself and Papyrus as well as Gaster on the opposing side. The vortex felt like it was pulling Gaster in with an incredible force, and at the same time crushing him with its potency! The vortex suddenly being overcome with an orange tint as Papyrus did the same motion as Sans, he used his orange magic to increase the potency of the spatial anomaly of Sans's as Gaster was pulled even more with it growing in size, his resistance becoming futile. 

Papyrus and sans both suddenly flicked the air forward and the ball along with it going and crashing right into Gaster resulting in him being dragged away and followed by a large explosion that could be seen throughout the entirety of the void with its potency.

For a moment the dust would settle and everything started to become clear as the energy slowly dimmed, but yet Gaster was not there. Both of them felt a sudden pressure on their shoulders as they turned around to see Gaster with a hand on each of their shoulders. His skeleton only slightly disfigured he had seemed relatively fine..

Gaster grabbed them both by the back and lifted them up into the air with one hand each and covered them in darkness. Gaster then threw them down into the ground, a crack noise being heard as both fell out of consciousness.

"Well it seems that the first test was a great success, I have learned much from both of you, exceptional performance. I just hope you'll keep going at this rate so we can crush that… demon." Gaster spoke with a sense of disdain in his tone as he looked off into the abyss.