Revertafter (achive)

https://www.deviantart.com/lazyodraw - link 
Revertafter is an AU that can occure when Sans/Errortale is defeated and restores his former AU "aftertale" to escape and survive through time and space.
== Storyline ==
Error was defeated, core frisk, had enough of the suffering he was causing, so she decided to make the entire omega timeline's characters teleport to the antivoid with one big attack ready to kill the destroyer, the plan was doing well, error didn't even had the time to realise, the attack was already on him, but he was not dying, it was way worst... he was unglitching he was becoming "sans" again, but he knew what would happen, when he would have got his sanity back he would have killed himself by remorse. He couldn't let this happen, so as a last move, in his rage and beaten, he opened a portal in his old au, or what was left of it, he broke into the code of it, and found the true reset of the world, but before doing this, he needed to make sure he wouldn't forget who he was, so he saved his memory in his head and used the true reset. But as he was severly damaged, he didn't saved it well, and lost it during the processes, only make him able to remember when he was asleep, but never able to remember it when he wake up.
== Character changes ==
Characters in order of appearance.
=== MORE COMING SOON ===
=== Sans ===
Sans is the first character you see when you enter the AU, when he reset he found himself in the ruins instead of the human, he will go the same way and teleport to snowdin as soon as he gets to Toriel. He won't remember how he got there and will walk home where he will fall into bed and sleep all day. Sans is not unlike his Undertale self, however he does have some differences in personality and powers, for example he likes to make jokes but will get angry quickly if no one is laughing, he is not as calm as he used to be and often gets angry over nothing, he also don't really care about his brother and when you answer "no" to the question "do you think my brother is cool ?" he will just answer by "well, can't say you're wrong". When he uses his powers in the genocidal and neutral end, he first tries to make strings appear from his eyes, unsuccessfully and will say he doesn't even know why he did it, he can use Gaster Blaster but most of them explode making them hard to control, his bones look normal, however, he can't control gravity like he used to and uses his blue magic like papyrus.
=== Frisk ===
Frisk will enter the underground like in undertale, by falling from the top of Mount Ebott, they will make their way from the ruins to New home while meeting the monsters of the underground one by one, and will either become friends with them, or kill them, there are two possible endings to this AU, the first is the Neutral where Frisk will kill or injure monsters along the way, or the genocide route where they will kill all the monsters in their path, whichever route they choose Sans' fight will be triggered in both, Frisk is normally armed with a rubber bullet pistol, until they find the real pistol in the skeleton brothers house in Sans' room.