You have a rainworld x undertale au? Do tell! Super interested!
Hmm i had a whole thing written and i took hours to write it and i was almost done telling you Frisk's life before they fell in my au but tumblr tumblred and deleted all of It 🥴 that's why it took me so long to answer this here lol i was mourning /j
Anyway i'll tell you a bit of it anyway. basically imagine the ancients were humans like two million years after our modern age. REMEMBER THIS. HUMANS = ANCIENTS. I WILL USE THESE WORDS INTERCHANGEABLY FROM THIS POINT. Everything happens as it usually would. The monsters get sealed (😔) time passed, Chara falls, except after they fall and That Entire Fiasco happens, the next humans to fall are spaced very far apart in time from each other. However, the Monsters don't know this because of Time Shenanigans. You know the drill. To them the normal amount of time between Frisk and Chara happens, and they think of humanity like us, not the ancients. The mountain is very conveniently placed in an area between different iterators, so it doesn't rain much there, by Rain world's standards. It does get all the other 'the earth is sinking' issues, but seeing as they quite literally live under a rock the Monsters still don't know this either. So now that ive finished making sure you know how for the monsters everything seems mostly the same except for the occasional odd item in the waterfall dump, let's move on to the ancients :)
They're still a whole hot mess, except they're humans. The whole legend about mount ebbot is forgotten, including what happened with Chara and Asriel, except maybe by the most avid mythology and history nerds. Again everything happens as it would, void fluid is discovered, religion religions everything, the iterators are built, the ancients ascend. Except not all of them want to ascend, and not all of them agreed with the iterator project ;)
I remember a pearl saying something about how some ancients decided to live on the surface despite the worsening conditions. I assumed they meant outside of the retaining wall. Now what if there was a movement about it? All those who disagreed with the iterator project AND all those who disagreed with the current way religious folks ran everything and promoted suffering in order to ascend decided they they were going to leave the iterator grounds when the Mass Ascension was announced. However they didn't come back once It was dome, because a big part of those who left disapproved of the iterators. Since they and the rest of the crowd couldn't afford to split up (they would likely die) and a lot of iterators already resented them for leaving like that and from the sparse communication they still kept, apparently would no longer host them they just decided to all stick together (not the entire population; think tribes and clans) and not go back to any of the iterators, be they willing or not. So they stayed out of the retaining grounds, as wandering tribes. The iterators see this and decide that anyone who helps an ancient will be labeled a traitor, since they (the ancients) wouldn't help them. (These decisions are made over a long period, not immediatly after the Mass Ascension). Of course there are many exceptions and many who disagree, but they mostly keep it a secret to avoid being ostracized.
Over time the ancients forget much of what brought them to live on the surface rather than above the clouds, and it all becomes stories told around the fire, with all the expected distortions of reality. Iterators basically become boogeymen lmao. Except they're very real, and in most tribes people are told to ignore the overseers lest they get taken away or cursed or modified or whatever.
Years and years pass and the whole Five Pebbles Fiasco also happens, Moon collapses (😔) and so on. Now we are paste Monk's time, but before the Rivulet is even born. So pebbsi is Not Doing So Hot but he also retains most of his processes.
Here comes a little child, like 8 years old or so in a tribe a few days' walk away from the outer expanse. They're very curious, always asking questions like 'why are the iterators evil' and 'why are we walking among ruins of cities' and 'what do mean we abandoned society for living in the cycle' and other such questions that aren't very easily answered. They're not very liked amongst the adults. This is also one of the tribes that clung to ascension religion the most (😔) so there's a lot of pressure to not let the natural urges happen without explanation as to why they have to do that. Which Frisk also asks questions about and is promptly told to just Do It and don't ask questions about it. They're a very adventurous child as well, and nobody really keeps much of an eye on them, so they often run off into the wild and come back days later if not found. The only reason they survive is often a scavenger or wandering slugcat (family) found them, went 'voids below that is a CHILD' and helped them not die until they were found or made it back. (Btw they all trade in this. Scavs🤝Slugcats🤝Humans. There is a bit of a feeling of superiority going on from scavs to slugcats and from humans to both scavs and slugcats, but if it came down to it you know none of them would take any shit from any other species. Relations are normal game relations between scavs and slugcats and read the above for humans with everything else, obviously sprinkled with a lot of wariness because oH nO ThEyRe WiLd aNiMaLs We CaNt TrUsT tHeM bLiNdlY. Only the second part of that sentence is completely true (that's just how things work in the wild i guess))
One funny day the tribe has decided to leave the place they're staying in because there's not enough resources to go around anymore. They're departing in a few days. Frisk does not know this and goes on one of their little adventure trips. By the time they come back the tribe is gone. (No one realized they weren't there, or they just didn't care. But either way they're alone now.)
They spend a few days waiting around, hoping someone comes back for them. They're good enough at foraging and hunting small animals (think baby centipedes, batflies) and making small fires that they do pretty well on their own for the time being. (This may sound unreasonable for an 8 year old, but keep in mind this is all they've been taught since birth, considering the nature of the settlements they've lived). When this doesn't work, they try to go looking for their tribe. They are unsuccessful, but they keep trying. For months. (What they don't know is, their clan went the way opposite of the outer expanse, while they went towards it. Although in circles, because they didn't know which way to go. That's why they take so long to get there.) One blessed evening, they find themselves in this lush and warm place (it's warmer as you get closer to the iterators). As they look for somewhere to stay the night they find a huge tree and oH THERES THANGS IN HERE.
The Thangs are Survivor and Monk, Who look at the very malnourished and very human child in front of them and think about it for exactly half a second before deciding to help them to the best of their ability. Frisk, who despite their skill, is still a child in the middle of a hostile wasteland, all but collapses at the promise of safety, even if they don't know yet what Surv and Monk are thinking. They just know slugcats are safe.
Aaand that's all for now! I have. A LOT more to tell before they finally fall in the underground but i aint rewriting all 'at
Extra trivia time!
Frisk isn't their name (yet) here. They have one of those excessively complicated ancient names here, but i haven't quite decided on it yet.
The atmosphere is extremely different from today's atmosphere. Humans didn't really evolve alongside it, so they have to wear masks that process the air for them in order to be able to breathe, under the ornamental masks, or incorporated within them. People are mostly able to scavenge or trade for the materials needed to make and repair them. Those who make masks are like the most important people in a clan, second to those who lead it.
Speaking of, the ornamental masks are still here! Although not as flashy as any you would have seen before the Mass ascension. They're also obviously not made from gold. Or metal usually either. Most are made of wood or bone from the animals they hunt. Occasionally people will have them made of metal, but that's for those leaders who are full of themselves. People will also make the mask prettier by hanging broken or otherwise useless pearls on them, or pretty rocks, plants, painting them, etc. They can be separated from the breathing part of the mask, and often are when hunting or foraging for example, unless they have an intimidation factor. Frisk has a carved and painted vulture mask to go with their breathing mask.
Frisk's breathing mask has been needing new filters for a while. You may understand where we would need to go to change and repair them in the absence of humans. ;)
Frisk is pretty good with spears and knives and weapons for a child. They don't do much damage though, think Gourmand when tired, but they can still lodge spears into walls if they try hard. Their time with slugcats and scavengers in the outer expanse will help them get even better and learn 💥movement tech💥. Or as much of it as they can since their weight center and strength is pretty different from a slugcat's.
When Frisk falls, they are absolutely gobsmacked, bamboozled, flabbergasted, astounded and astonished to see a house that isn't in ruins. They are even more flabbergasted to see a society that is full of stable, warm houses that don't move. They are even more surprised at regular house appliances. The discovery of yet another intelligent species doesn't surprise them as much as it should compared to all this. (Toriel is very worried about their wonder at normal everyday things)
The Mark of Communication allows those who have it to understand every language, but not speak it. Frisk is very quiet in their first few weeks in the underground, while they absorb the vocabulary (Toriel is also worried about this, but less since she has met kids who didn't like to speak before). The Monk and the Survivor can understand Frisk regardless of the language they speak thankfully so they don't have as many problems there even before they could speak fluent slugspeak. Or scavspeak. (Yes they are mostly sign based languages 😌)
Don't ask me how the cycle works in this au pretty please 🥰 all i know for now is Monsters are still bound to it, but in a different way to everything else in the world.
Frisk can speak, but often would rather sign. This won't come up much in the story though, it was mostly only bothering them when they were around other humans. Yes they are autistic no humans do not know what autism is.
Undyne will be Thrilled™ to see their skill in evading and fighting. Especially since they already have a spear. ("Finally a worthy opponent! Our battle will be legendary!" But the opponent is still a very pacifist child. [I'll explain how this happens in another post. Hopefully.])
When i say the ancients are humans i don't mean like us. They're still very much looking like the murals, at least before the Mass ascension. ...Well mostly the wealthy, but the human genetic code has been altered to hell and back so the poor didn't look too different anyway. While lot of it doesn't show after generations of not-human traits not being activated and reactivated and added, Frisk does have features that aren't quite normal for today's human beings. For example, their skin is adapted to the weather, they retain warmth easily, and they can see better in the dark than we do. There's also cosmetic oddities, but i haven't decided on those. There's more traits that are in their DNA that could be activated, but there is no way or reason to in their current situation.
Frisk is no longer eight by the time they fall. They are nine or ten, but if they're nine they're on the older side of it.
I think that's all. If anyone who sees this has any questions, about Rain World or about undertale or about this crossover in particular, feel free to ask in the comments or with a reblog or an ask! I would love to talk about this but i am terribly undermotivated. I have so many ideas and so little patience to say them........
Lastly:
Are you reading this part of the Undertale fandom or the Rain World fandom?
Undertale (hi??????😃)
Rain World (based)