|“||Aww. It was a limited edition.||„|
|~ Sans after X-Tale!Chara destroys his ketchup bottle.|
Sans (also referred to as Classic!Sans) is the main protagonist of Underverse, and makes a cameo in X-Tale. When half of his soul is taken by Cross/Cross!Chara, Sans ends up going on a mission to rescue his soul, but as time goes on, he begins to know more on what the two actually are, and their true purpose.
Sans's appearance is only brief; when X-Tale!Frisk shows X-Tale!Sans his own universe, Sans is seen with Frisk, and as they all drive off, Frisk wants a picnic with all of them, a foreshadowing to what happens next.
Once he wakes up in a strange area, he wonder how many times he's been in weird dimensions, and after walking a while, he comes upon Cross, who tells him that his timeline will not change when he becomes part of it. When he reveals that he's him, he has a gut reaction, pulling his Gaster Blasters out. Cross!Chara tries to calm him down, saying that he needed a place to stay for a while, which Sans doesn't really find amusing, and runs off. He doesn't get that far, as Cross pulls him back to take half of his own soul. Once the two return to his universe, Ink!Sans comes in to save the day, but is unable to take the soul back, as Cross!Chara leaves for their own universe.
Ink!Sans soon explains to him who was Cross exactly, saying that they haven't done this type of act before. Sans isn't all too worried, as they're still able to function well even without half of his soul, but during a volleyball playoff where Sans, Papyrus, and Frisk were up against Undyne, Alphys, and Asgore, Sans is unable to dodge the volleyball Undyne threw at them, and he visions XGaster as he falls to the ground.
He heads over to Ink's paint puddle, asking for him to take him, but Frisk ends up suspicious about this, and confront Sans one by one. After finding out that he has only half a soul, Frisk suggested to reset the game, to which Sans rejects in front of Ink. With the story told, Frisk wants to help the both of them find Cross, but he tells them to watch over them while he finds his soul, promising to visit them while he goes on a rescue mission. Frisk hands him a limited edition ketchup bottle for Sans, citing it'll be useful for him.
After taking a nap, he's shocked that he's back in "Snowdin", but he quickly realized that this wasn't his Snowdin, but Underfell's. As the two progress further towards Snowdin Town, Sans once again glitches out thanks to Cross, and once Underfell!Sans impales him, he begins to feel the same way too, as if he were stabbed himself.
Once the two get to the town, Sans decides to act as Ink's pawn, where Cross takes control of Underfell!Sans to act as his pawn. The two fight over each other, and after Underfell!Sans is tied up by Ink, he soon begins to explain to Cross that he needs a nap, and explains to him about seeing XGaster out of nowhere. Once Underfell!Sans get loose from Ink, he uses his special attack on Cross: his slipper. It was enough to distract them to allow Underfell!Sans to be freed from his control. Once Ink is taken by surprise by Error!Sans, he decides to take a break and leave, which Underfell!Sans follows once his brother threatened to use his head for his spaghetti.
While on break, Core!Frisk tells him that in order to defeat Cross, he needs to distract them. As Underfell!Sans comes with him, he jokingly uses the echo flowers to annoy him. Once Ink leaves from Error!Sans, Sans suggests that they should go to his universe, which Ink tells him that's impossible considering that X-Tale is now a empty world where finding Cross would be difficult to do, plus the fact that he has half a soul. Dream!Sans does tell the 3 of them where Cross is heading to next for his X-Event performance.
Once in Underswap, Underswap!Sans believed that he has created clones, but recognizes Ink, who tells him that Sans and Underfell!Sans are going to die soon. All of them head downtown to find that Underswap!Toriel was slashed in her left eye. As Underswap!Chara heads to the scene, Sans tells Underfell!Sans regarding his plan. It works; Cross is defeated, and Sans gets his soul back. His plans goes to waste, however, when Cross!Chara adsorbs a majority of Underswap!Chara's soul. When Sans questioned Ink regarding X-Tale!Chara being his friend, X-Tale!Chara sends him and Underfell!Sans to X-Tale.
As the both of them struggle to get out, Dream!Sans shows up, asking them to stop feeling negative, as he can't get them out of here and head back to Underswap, even reminding Sans that he's filled with hatred. Once Underswap!Papyrus starts thinking about how this timeline was the best they could be in, Dream!Sans is able to enter with the both of them, and once Sans saw the situation and how it was giving him déjà vu, he blocked X-Tale!Chara's path of strike, at a cost of his ketchup bottle. He then battles it off with X-Tale!Chara, even giving back Underswap!Chara some of their soul back.
X-Tale!Chara explains to Sans if he's worried over all of his other "Sans", and explains that his world isn't what it seems to be. Before he could get any further to convince Sans to kill Ink, he's stopped by Nightmare!Sans, who stabs Underswap!Chara and takes X-Tale!Chara with him. With the timeline collapsing with Underswap!Chara's death, Sans takes Underswap!Sans to where Dream!Sans is taking the rest of the gang to.
Sans only makes a cameo in Xtra Scene 2, appearing just as Ink invades Undernovela and overwrites Asgoro and Sins.
Sans is first seen in Outertale along with Underfell!Sans and Underswap!Sans. He listens to their conversation about what happened when they both got involved with Cross or X-Tale!Chara, though his eye sockets go completely black once XGaster is mentioned. He eventually changes the subject, and Underfell!Sans remarks that Ink had disappeared again. Sans decides to go explore Outertale to look for Ink, and he tells the two other Sanses to make sure that they won't be seen by anyone.
As he explores, Sans sits against a brick wall and takes out his heart locket. He remembers X-Tale!Chara's words ("...Just one world with the best of the others. Just one Universe...") and grows angry, saying that he already has enough tension in his own universe.
He overhears some monsters talking about a meteor shower in the distance, and he stands up to watch. As he does so, he hears a voice from behind him, encouraging him to introduce himself. The voice turned out to be Outertale!Sans, and after an unexpected greeting involving two whoopie cushions, the two begin to conversate a bit. Sans asks if counterpart from space had seen another Sans in a different outfit, and Outertale!Sans says that he hasn't.
The two walk around the place, and Outertale!Sans talks about his universe and his Papyrus. Sans interrupts him, calling him lucky because he can see the stars all the time. After a brief discussion, Outertale!Sans spots Killer!Sans and asks Sans if that was who he was looking for. Sans denies it and tells the other Sans to not interfere. After eavesdropping, the two realize that Killer!Sans, Error!Sans, Nightmare!Sans, and X-Tale!Chara were all aware of their presence. After Outertale!Sans sacrifices himself to fight Killer!Sans, Sans manages to teleport back to Underfell!Sans and Underswap!Sans, telling them that they need to leave. After a comment from Underfell!Sans, Error manages to find them and tie their SOULs up in his strings.
During Error and Ink's confrontation, Ink remarks that Classic!Sans, Underfell!Sans, and Underswap!Sans were not his friends. Underfell!Sans angrily yells that Ink betrayed them, but Sans tells him that it was always his idea.
After an explanation from X-Tale!Chara and an angry outburst from Error, Ink makes the first move to attack Error. Error uses Classic!Sans, Underfell!Sans, and Underswap!Sans in order to attack Ink with their Gaster Blasters, but that plan eventually backfires once Ink releases them and their SOULs from the bonds of Error's strings. After a while of fighting, Ink begins to explain his plan with the game once Underswap!Sans tells him that he should wish to protect the AUs instead of intervening like he was. Sans tells him that he won't be able to enjoy the possibilities if he was emotionless, and Ink replies that it won't be like this forever before dropping the vial holding XGaster's SOUL and releasing him.
While being confronted by XGaster, Sans watches in horror as he shatters Underswap!Sans and Underfell!Sans' SOULs before he is brought back to his own timeline, with everybody from his universe watching him in confusion.
As a regular Sans, he dons his blue jacket, a pair of shorts, a white T-shirt, and a pair of pink slipper, which he calls "his special attack". Something he also wears is a heart locket, with a image of the Undertale characters. X-Tale!Chara finds this out of place, being the reason why Cross told him that heart locket wasn't his.
Like any normal Sans, he's able to use blue attacks, bone attacks, Gaster Blasters and teleportation.
Sans may have characteristics of a lazybone, but he isn't that scared to show his serious side. When Frisk suggest to reset, Sans tells him not to, in front of Ink. Meanwhile, when he gets to Underswap, his left eye shined directly at Underswap!Chara, possibly indicating that he's been through a genocide run before, which X-Tale!Chara might have hinted at with him when he said his timeline wasn't working as usually.
| X-Tale: Cross | X-Event!Chara | X-Event!Frisk | XGaster | X-Tale!Papyrus | X-Tale!Undyne | X-Tale!Toriel | X-Tale!Asgore | X-Tale!Asriel | X-Tale!Mettaton | X-Tale!Alphys