... (Picks up a megaphone, turns it on and brings it to my lips) I do not own either Bleach or Undertale!Those two seperate subjects are the rightful property of their legal owners! This story is for entertainment purposes only!

...

At any rate, this idea popped into my head around the same time I noticed there was no Bleach/Tenchi Muyo GXP stories when I was exploring... (Bonetrousle (Undertale) begins to play) SO GLORY IS ONCE AGAIN MINE! FIRST! NYEH HEH HEH!

(Music ends) Also on a side note: for those interested in Undertale related online comics, I would personally recommend Aftertale by Loverofpiggies (or at least I think that's her(?) name). Also, looked into it originally because I was curious, Underfell by Kaitogirl(?), both of which are on tumblr...

(Post note) Interestingly enough as I was posting this, I discovered you can't post/type links...

Also, this story is meant to be a one shot, an inspiration if you will much like (and partially inspired by) DOOM DXD(2016) by Gunkatas (you evil bastard... GO ALL OUT ON IT ALREADY! (also mildly aware of the hypocrisy of me saying this, mind you). It might turn into a full-fledged story down the road but that largely depends on whether or not anyone else will take the bait and write B/UT stories as well as how interested I am at that point in time. With that, I hope you enjoy the story!

Sans Determination

A backwater station

There weren't many left. In fact of the hundreds upon thousands that lived within the entirety of the Underground she could count perhaps twenty or so survivors with herself on short notice, including herself if she actually bothered to count. Well, twenty or so that was with her... If there were other survivors then they were well hidden, out of side and more importantly away from the terror she still continued to watch in horrid fascination since it had first appeared with the forest near Snowdin... the Monster in human form.

Whatever its reasoning, it mercilessly destroyed one monster after another with a slowly growing grin on its face as its eyes grew darker with bloodlust made obvious whenever they tried to stop it. Even a passive Papyrus was torn apart once he barred the human entry to the Waterfall region.

Even Undyne fell against the human's butchery.

Since her fall the evacuation had been officially sounded. Only a few remained behind, mostly what composed as the remainder of the Royal Guard now that most of their forces were slaughtered and a few brave holdouts trying to buy everyone else time. Even Mettaton took up arms, after having his body heavily upgraded for combat of course.

... Now all the remained of the Underground's forces was King Asgore himself in the throne room, and, surprisingly, Sans in the hallway just before it.

At first she thought he would be utterly annihilated just like everyone else before they could throw the first punch. But no. He dodged and retaliated. He did what only Undyne was able to do, harm the human, made it bleed for a change. And so the battle raged on; evasions, attacks, stalls, advances, retreats... What hope she had felt arise at seeing someone finally challenge and match the human was quashed unlike the others as she noticed something they hadn't: Sans, for all his agility, tricks and tactics, he was losing. His abilities were being read and memorized. His blasters, the Gaster Blasters he almost never used on anything were missing their mark. And Sans... he was tiring, getting slower despite that constant, perpetual grin on his face that would have others think otherwise... It wouldn't be too long before he became a victim himself. As such she had long left the crowd that gathered around the TV, letting them cheer and enjoy their hope for a bit longer as she got to work scrutinizing the lab before her.

Originally it wasn't hers when she came upon it, but she made her own style of improvements of the years. From what she gathered it once belonged to... the previous Royal Scientist. As such it was originally only filled with spare parts, schematics, notes, a tarp covered device and even a spare bed. Whether or not he lived here beforehand or simply gained this building for his own use as something of a second lab or a storage building, perhaps something of a retreat even, she could not tell. In fact in her attempts to discern what interest he had in it it seemed that no one knew of it at all. Not even the king! Sadly though it seemed he had written all his notes in code. One which she couldn't make heads or tails of considering the system consisted solely of hand signs, bombs, arrow signs, trashcans and all sorts of other symbols. She tried to find a cipher in her spare time within the other notes, which her also coded, the trash, inside the walls even but to this day she had no luck in deciphering what he was saying. In the end though she had to make do with semi-crude drawings that had been left behind in his wake, all of which consisted of that machine he kept in the corner. As such all of her research concerning the previous Royal Scientist focused on the machine.

From what she had discerned it was some form of an early attempt to break through the barrier that trapped them in the Underground. The idea, in theory, was to literally teleport one person to the other side at a specified geographical point in the human world above. The drawings however did not show if it was ever tested however. For all she knew he had, deemed it a failure and left it to collect dust after having the tarp thrown over it. Then again it seemed like some components were missing at the time she had first uncovered it. On top of that it lacked a power source of any kind. It could be he simply had to put it on hold and... never got around to finishing it. It was a plausible theory at least. Regardless, over the years she had been tinkering with that machine, and empowered it with cables straight from the core itself for better or worse... she just never thought she would actually entertain the idea of using it.

Considering her mistakes, she wasn't anywhere eager to use what could very well be an untested side project build upon theory. And say it does work as it was thought to, wouldn't they be trading one situation for another? In an unfamiliar world no less? On that bred the very creature that Sans was now fighting against!

"NO!"

She jerked her attention back to the TV and gaped at what had the morbidly enthralled crowd were staring at in dawning horror; Sans, sitting in front of the human, clutching at a heavy perpendicular slash across his chest. From both his wound and from his mouth came a dribble of blood, staining once pristine bone and clothes alike as he heavily breathed. All the while he still kept that famous grin on his face. Yet anyone could tell they held a forced, pseudo-mirth that only matched the pained, defeated and sorrowful stare he gave his attacker as if he knew something worse would happen than his death... In fact, from the rumblings of the TV, it seemed that he was speaking to the human with his dying breath.

As Alphys gaped at the image of Sans standing up, a sickened pit arose within her stomach... one that urged her to act... With grit teeth and tears in her eyes she turned to the machine, undone the tarp and began to madly push buttons and pull levers with only half a mind being concerned with what she was about to do. Though there was by no means a guarantee of a better life or even a modicum of protection awaiting them should the machine work, but something demanded that she'd act. A primal instinct perhaps warning her of an unstoppable danger to come? Or perhaps that their days were numbered should they be confined with an colossal cavern with only so many places to hide in the end from a relentless killer? She couldn't tell, nor did she care to as she brought the machine to life and pulled on one last lever.

That was the last thing she could see was the fading silhouette of her own hand still grasping the lever the very moment a soundless light erupted from the machine in a surging dome.

XVX

Judgment Hall

"welp. i'm going to grillby's."

The human didn't respond. In fact it ignored him as he limped passed it, likewise being passed in return. The human didn't even bother giving him a second glance, much less a look over its shoulder as he lumbered as far as he could as his body fell apart. He only stopped when he literally felt he could no longer take step without collapsing and turning into dust like so many before him. With his labored smile still in place he looked up at the wall before him with unfocused eyes as his 'lips' twitched with sardonic amusement. "papryus, do you want anything?"

Shoo!

The last thing his unfocused eyes saw was a curve wall of wall light silently rushing towards him. Was this the end he and every fallen monster was embraced with? He would've smiled if he still had a mouth.

XVX

...

As if he were sleeping and someone shook him awake with a boom box cranked to max RIGHT NEXT TO HIS 'EAR' he jerked to a start and stupidly stared at his new surroundings. Wherever he was he was in what appeared to be a city of towering structures with a great many windows for each floor. Some of which it seemed the buildings were entirely covered with nothing but windows. But that was neither here nor there as he came to stare at the sole inhabitant of the city. One who was far more openly confused than himself on an off day.

It was a human much like the one he was just fighting against a little while ago... sort of at least. Same species. He was obviously far taller than the human he was fighting before, especially since said human was about the same size as the skeleton himself. He also had orange, spiky hair, a sharp contrast to the plain brown hair of the human. He was also scowling in confusion as he looked about, a far more emotional reaction when compared to the often expressionless or else murderous face of the human.

"... Who are you?"

Lastly, the final difference between the human from before and the one now was the fact that this one was willing to converse with him.

"hey. i'm sans. sans the skeleton. nice to meet'cha."

"Uh... Ichigo." He pursed his lips in a frown. "I'm sorry but what was your name again?"

"sans. why?"

Frowning still, he brought a pair of fingers up to his ear and snapped them twice. Satisfied, he did the same with the other ear. "One more time please?"

"... it's sans... why?" the skeleton answered and asked evenly. He would've raised an eyebrow if he could. His smile even threatened to turn into a confused frown of its own...

In response Ichigo groaned irritably and began to run his hand through his hair. "Just for whatever reason I just can't hear your name."

"huh... that's definitely weird." He pocketed his hands within his jacket as he continued to grin at him. "you swure you don't have a hearing problem?" He winked good naturedly at the teenager to help emphasize it was a joke. In response the teenager scowled at him and began to look around again in confusion.

"something buggin' ya, kid?" he asked after a moment. He joined in and looked around himself in hopes of ascertaining what Ichigo was looking for. He never let the human out of his sight though.

'No it's... I'm just not sure what to do here," the teenager grumbled as he began to circle in place in evident confusion.

"what'cha mean?"

"Just... I don't know..." He growled and clutched at his chest, eying it with worry before looking to his surroundings once more. "All that makes sense right now is that maybe I have to do something in this place to become a Soul Reaper."

While he had no idea what a "Soul Reaper" was, he quietly tensed. Though the human appeared to have no aggressive intent and at best gawked at him for a good moment before turning to his own devices, his recent experience with the human before was not something to ignore at the first 'friendly' face he seen in regards to humans. His attention was soon diverted however as the entirety of the city they stood in shook without warning as if something had crashed nearby. Both looked around in mild hopes of finding the cause when a noise from above drew their attention. Looking up, Ichigo gaped at the fact that some of the towers were now collapsing. What's more, the pieces that fell off, including the windows without shattering, were turning into white boxes of the exact same size. Sans for his part only continued his grin out of sheer force of habit, though sweat did dot the side of his skull. If things weren't bad an confusing enough the other buildings began to share a similar fate as they too began to crumbled into boxes. In a matter of moments the avalanche of boxes crashed into the street and began to flood it.

"Crap! What the hell is happening?!"

"heh... i guess certainly qualifies as a boxing development," Sans chuckled as he looked for a feasible escape route— try as he might, he couldn't teleport himself anywhere. Ichigo in the meantime could only panic as a tidal wave of boxes bore down on them. To make matters worse the ground beneath their very feet was darkening and deteriorating till there was nothing but a hole left behind. As such they fell through when it expanded too quickly to be dodged. Thankfully the abyss that loomed underneath was aquatic in nature, cushioning their landing with little in the way of discomfort. For better or worse though they were being drawn to the depths by some unseen force where several boxes were lazily floating within the water-like material that enveloped them without choking either of them in the slightest. Even then their number grew as the wave of boxes from above began to filter down towards them.

Like before they were looking around their surroundings in evident, in one case open, confusion. Seeing that there was nothing better to do, San's swam unimpeded to a box and patted it as he came to inspect it. On a random thought he grabbed the box with both hands and opened the box-like object just like a regular box. Out of curiosity he peeked his head inside. He almost pulled his head out the moment he did as he all but rammed his own face into the face of an obviously older human. One with a scraggly beard, dark hair and wearing tinted sunglasses with no frames. The two simply stared at each other for a moment before Sans pulled his head out and closed the box. "don't even want to know."

The sound of boxes being opened drew his attention back to the orange haired human as he opened the boxes almost as soon as he reached them. He peered inside each and every one he opened for a brief moment before scowling and kicking off to another.

"looking for something?"

"Kind of," he answered ina distracted fashion as he opened another box, scowled, and drafted off to another.

"... do you even know what you're looking for?"

"Not really," Ichigo admitted as he relentlessly continued his search.

He held up the box with the man's head in it. "i found a head in the box if you want it."

That actually stopped the teenager to glare at him in a deadpan expression. "You're kidding me..."

"nope." He looked to the box with his never changing grin before looking to Ichigo. "you sure you don't want to get a head?" He held the box up and shook it. Listening carefully he could almost hear something akin to a discomforted grunt emanating from the box.

"I'd rather not," Ichigo retorted dryly before resuming his search. Shrugging, Sans let go of the box and watched it float. Once he was board with that he lazily swam to another box and opened it. Unlike the one before it was empty. Not wanting to unnecessarily agitate him as well as just not feeling like it, he left it open and swam away.

"What the..."

With a curious hum Sans looked toward the human and found him staring into a box. More specifically he was staring at something poking out of the box. A bone-white something with an irregular shape... one that seemed familiar to him. He began to swim toward him at a slow pace to get a better look at it when the human took a hold of it with both hands and began to pull. By the time he drew close to him the human managed to wring out the object...

If he could, he would've paled in surprise as the human pulled out one of his Gaster Blasters from the box. Just as he began to inspect the oblong, animalistic skull it began to disintegrate within his hands like sand caught in the wind. Instead of being blown away however, the currents the particles rode in on crept out to Ichigo and tethered themselves to him.

Then the world shook once more...

XVX

Again he jerked in place with a start and blinked. Gone was the human. Gone was the dark abyss and the boxes. Once more he was on a street in a city. It was different however. Namely there were no towering buildings of stone and glass. No. Instead he was in a city of a rustic and familiar feel to it. One with cobblestone streets and mason work that was all too similar to New Home. Unlike New Home there was no looming cavern ceiling overhead. Just blue skies...

A rarely seen frown finally broken through his facade as he walked forward and eyed his surroundings in hopes of discerning what had happened. Perhaps find someone if he was lucky who would at least tell him where he was. In his search In his search he almost completely bypassed a store window had he not eyed something unusual about it. When he eyed it he saw an image of what appeared to be human children and an older one staring back at him. At least that is what it looked like. Upon closer inspection in the literally sense he noticed there was indeed something of a height difference in where they were staring and his own height. The children appeared to be gob smacked about something whereas the adult withdrew a fan from the confines of his robes and unfolded it. He would've watched more of the scene, especially since the 'camera' as it were moved with incredible speed, but movement at the corner of his eye had forced an automatic reappearance of his smile as he looked to his side. Sure enough the old man from the box was there some distance away with a frown on his lips as he eyed him in return.

When the man's lenses tilted up at the sight of something else he turned around. Sure enough he had another person for company... Only...

Whatever it was, it looked like an exact copy of Ichigo. Only in robes. And with a giant knife strapped to its back. And made positively white in all aspects from his skin tone to his clothing sans a black sash of a belt and wrappings for the knife. On top of it all the sclera of his eyes were black which made his yellow irises stand out all the more. Unlike Ichigo, this... thing... reminded him all too much of the 'human' that slaughtered its way to New Home... The smug, eerie, bloodthirsty smile on its face did it no favors in helping him think otherwise. Nor the fact it was now drawing out the knife helping him ease his nerves.

Sighing to himself he lowered his head and walked out onto the street proper. When he reached the center of the road turned to the lookalike, his ever present smile on his face. "hey there. i'm sans. sans the skeleton," he introduced himself. The white colored Ichigo scoffed and sneered at him in return as he not only shouldered his weapon of choice but cracked his neck quite audibly as well. "listen," he lowered his head and closed his eyes, "i've had something of a long day. a long day of heartaches, of fights and weirdness starting with talking to that ichigo kid. let's just settle down for a moment before we do something... rash here. what do ya say?"

The specter of a teenager grinned maliciously at him and scoffed. "Jeez, you stand in my way and have the gall to ask me to "settle down"?" He pointed the blade at him with a distinct "woosh" to emphasize the power and bloodthirst behind the strike. "You've got some real nerve there, buddy."

The skeleton sighed. "welp. can't say I didn't try to reason with ya." He looked up at the pale copy. "at least let me ask this, buddy, do you want to have a bad time?" With a battle cry the white version of the teenager charged at him, bringing the blackened edge of the knife to bear down on him. He didn't stop to hesitate in the least when a ring of blue encircled the iris of his left eye socket and thrummed with power. "don't say I didn't warn you."

A/N: Bit of an anecdotal story: found a UT personality quiz on youtube once. Scored as Sans. So I guess you could say I have a personal interest in this.(*Wink.*) (Titled "Which UNDERTALE Character Are You?" if anyone is interested)

Here's something of a schematic, guidelines rather, for anyone who's going to more or less use my story as a base of sorts (SPOILER if I continue this story! (Skip to the end if you don't want to read the next paragraph!):

Following more classical zanpakuto rules, Ichigo can use San's powers in the open world as his Shikai. Sounds like it would be great against multiple opponents, right? Especially close-range types? Sure. But let's face it, you're defense is only as great as your awareness and forethought if absolutely nothing else. In other words in certain situations on a theoretical level someone with San's abilities can easily get overwhelmed if the enemy is, say, too fast, at an extreme range, or simply outnumbered; on an individual level San's abilities are essentially a curb stomp battle for the other guy. If you disagree then I suggest watching San's fight in the game and then apply that to the Bleach Universe. At any rate, as you may have guessed Ichigo's Bankei state would be the more classical state of fighting in the UT universe, only they're in a pocket dimension where Ichigo is essentially invulnerable until the enemy's turn.

Anyway...

Monkeybandit2, punning off with your attention! No refunds.