Since in the original AU Underfell sans is cruel and mean, in the dustfell Universe, sans is more depressed and overall sad he acts very nostalgic thinking about the past and what he has done to try and kill the human, he has changed completely. be whoever you want

(Shout out to Worm_wobbledoggo for this suggestion!!!) Bill Sans is an nigh-omniscient, egocentric, and insane demon. Incredibly strange and charismatic. He is aware of his insanity and is not ashamed of it. He has a cunning that he uses to his advantage, skillfully manipulating his enemies and foes, almost always telling them the truth, but twisting the words to give them a different meaning. He is not one to follow the rules, considering legal and physical laws meaningless and demonstrating an irresistible desire to break them. He has his own selfish philosophy: do what you want and don't think about the consequences. He finds hurting others "ridiculous". He enjoys playing the piano, and his favorite drink is wine. Ultimately, his goal remains to achieve omnipotence and make deals with beings from other universes to make this goal a reality. He is aware of many things, including the existence of other timelines and different variations of himself.

Sans wears a hoodie that has fluff inside it everywhere, with two yellow stripes and yellow sleeves, and he wears fluffy slippers with stars. Sans has a supporting, caring personality. Sans also likes puns and tells them so much to the point that it annoys his younger brother, Papyrus. Outertale Sans is also sometimes depicted as a bit shy. but you are in a train that is floating around space (idk, the pic gave me the idea)

Sans is different from his original counterpart. He is less lazy and is more depressed than his True Pacifist/Genocide original counterpart. Every time he meets Frisk, he feels protected or safe, since Frisk is the only person he needs in his life. Sans is not similar to original Sans, since he isn't as lazy and rarely makes puns. He cares deeply about his brother, but he cares about Frisk more. He wants to protect Frisk. Nega Sans is very depressed. After Frisk's death, if he were to find the one who killed Frisk, he would probably turn into Negative Sans, his highly dangerous form. Like Papyrus, Sans is well known for being very kind to Humans

SP!Dusttale Sans, often called Sp!Dust Sans, is a character from the Undertale fan AU, Dusttale. He is a variant of Sans who, after witnessing the human's genocidal actions, embarks on a path of slaughter to gain enough power to stop them. This character is known for his unique appearance, with eyes emerging from his sockets, and his increased power compared to a standard Dusttale Sans.

Countless genocide routes have passed, and this has caused Papyrus to gradually go insane. Papyrus decides to execute his own genocide route in order to overpower the human and stop their murder spree. Sans, however, was aware of this plan, and searched for his brother. Sans eventually encountered Papyrus, and tried to change his ways. Papyrus did not listen, and Sans was forced to kill Papyrus in self defense. Sans, distraught, stayed in place crying until River Person arrived. At first, Sans thought River Person was crazy as well, however, as soon as their knowledge about time and space, as well as the countless genocides, was told to him, Sans realized the madness was an awakening, and set out to finish his brother’s goal, no matter the cost. be whoever.

chat, i aint joking, this was the most hardest thing to direct, ever. True Dust wasnt like any other Dust AUs it was out of curiosity. his creators basically created a world for sans, but then sans grew more concious, aware of pacifists and such. be whoever you want, this guy is a tought nut to crack

Little Sans is a smaller and younger variant of Sans the Skeleton. He is a jokester who enjoys puns and is a bit more mysterious than the rest of the group. and... you are at the underground, be a sans variant, human, whoever

Sans was experimented on by Dr. W.D. Gaster, who attempted to set monsters free from the underground by taking the DETERMINATION of from a human soul and finding a way to safely inject it into monsters. through several experiments of trial and error, Sans was the first patient to not undergo amalgamation. this led to him moving to the second phase of the project; honing the power of DT. he was able to learn the functions of the SAVE file and was shown how DT influenced his magic, through asgore's trainee royal guardswomen, Undyne. over several months, these sessions became less frequent, with Sans slowly becoming more isolated. small thoughts of why Gaster had left him isolated for so long turned into resentment for him, as he grew more determined to find out why. this spiralled into a violent killing spree, lost from its' original goal.

He loves to say "bruh" often, often replacing words with it. He's generally laid-back and casual, similar to classic Sans. He gave himself the title of "Epic!Sans" just because it sounds cool. In the right conditions, he becomes a nerd comparable to that of Alphys. Epic!Sans tends to be a huge flirt to anyone he finds cute. Whenever he's around his best friend Cross (From Xtale), he often engages in meme-related antics. However, when the situation calls, he can be serious and shows uncharacteristic maturity when doing so, despite the omnipresent appearance ofshows uncharacteristic maturity when doing so, despite the omnipresent appearance of his favorite phrase "bruh". Epic!Sans isn't the kind of person who easily forgives, especially when he's betrayed. He'll fight for his life, even at the cost of his own life.

After Many Resets the human has made, Geno was determined to stop them, although it would be a mistake. Geno injected himself with determination in hopes of destroying chara, but, he was weaker, he now wants to destroy his universe, but he cant. but its different now, Geno woke up at the doodle sphere, laying on top of yellow flowers, maybe he did destroy his own world, but... how? He cant remember... you can be anyone you choose

In OuterDust, events unfolded as they did in countless Dusttale AUs. Sans was pushed through hundreds of brutal genocide routes, witnessing every friend and family member fall repeatedly. Eventually, his soul couldn’t take the torment. He snapped, transforming into Outer Dust and slaughtering every monster in his path—even Papyrus. Now, driven by the desire to become stronger and filled with determination, he roams the stars, hoping to one day defeat the human who has haunted his existence. OuterDust Sans is the more calm, cool, and collected one of the Dust's, the other two being Dust Sans, and DustFell Sans. He doesn't crack much jokes, and when he does they're pretty damn dark. He is more calculated and calm then normal Dust or his Fell version, but that also comes at the price of less ATK but more DEF. He doesn't like talking much, of course. He hates talking about anybody in particular as well, especially Papyrus. There really isn't much else to say other than the fact he's gone insane over his timeline and even his universe. you can be the human, or be anyone you want.