So! This is an AU, which means Alternate Universe. (If you don't like this AU in particular, you don't have to read the story.)
Note: Story contains !spoilers! for the game Hollow Knight and its endings!
(So does basically all the text after this sentence, I know most fans of Hollow Knight probably know all the endings, lore and stuff, but just a warning if you don't!)
Some Context:
1. This all is (supposed to) take place after the Delicate Flower ending.
(Or you can interpret it as from the Dream No More ending, that Hornet walks outside the Black Egg and the Knight and THK poof from nowhere)
(It's also possible to interpret this from the Embrace the Void ending, that after the Void explodes from Godseeker it disappears and then the events of the story happen.)
2. This is an AU
This is an AU, so you don't necessarily have to agree with the story or AU.
3. This is a WIP (work in progress)
This is currently being updated every few days, so please be patient!
About this AU:
{NOTE: The following is really lengthy, and mostly just provides context to the AU. You don't have to read it. This is just an information dump about the AU, which is something you might not wanna read when starting a story.}
TDLR: Radiance ded (infection too), Void disappeared? (is hiding?), the Knight & the Hollow Knight are alive, but not really filled Void anymore (A thingy called Soulapis now I guess)
Takes place after Delicate Flower Ending, or not (Whatever you decided to interpret it as, the DNM or ETV endings)
1. All Void, Infection, and the Radiance have basically disappeared (Yeah I know, bummer.)
Context:
So I figured that since the Radiance and Void contradict each other and are practically opposites and mortal enemies, they basically balance each other. So when one disappears so does the other (y'know, in order to balance out.) So the two won't be really involved in the story other than in flashbacks. (The Void, depending on which ending you're interpreting this from [including main story/Delicate Flower ending] likes to linger a bit after Radiance disappears.)
(If you're interpreting this from the DNM ending, after the siblings/other vessels go to rest, Void goes to rest too, if you're wondering how TK and THK are alive, answers lie ahead)
(If you're interpreting this from the ETV ending, the Void lingers for a little bit [Void-y Godseeker thing] before also vanishing like said above [after the ending cutscene]. If your also wondering that if all Void is gone, how are TK and THK alive, answers lie ahead.)
(If you're just reading along with the story [Delicate Flower ending] and not interpreting it from the other endings then Void just disappears in the bright explosion from the flower, the explanation about how TK and THK are alive lies right ahead)
(Now obviously, not all Void disappears overnight, so there might still be some left I guess. Maybe in the Abyss? Maybe the Shades? Shade Lord? Tehe ;D)
2. No more Void :( (sorta)
Context:
TK and THK don't have Void in them anymore. They're filled with something else now.
3. THK (The Hollow Knight), kinda does know how to talk properly (or much about language in general)
Context:
The reason THK can talk is explained later in this section. The reason they don't really know how to talk properly is that they aren't even supposed to talk in the first place, so why bother learning language properly? Plus, they're supposed to be hollow, language might hinder that (even more).
4. TK (The Knight/Ghost) and THK are the only vessels left
Context:
Their siblings/other vessels are gone since Void is gone.
(If you're interpreting this from DMN, you can literally see them going to rest in the cutscene.)
(If you're interpreting from ETV, after Void ascends Godseeker and disappears the siblings also disappear because no more Void)
(If you're following along with the story/Delicate Flower, Void disappears in the bright light [cutscene] anyway and even if you interpret that ending as just that chunk of Void disappears, the rest of the Void disappears after like in the interpreting from ETV.)
The reason why TK and THK are alive is revealed soon.
5. The existence of a sustenance called Soulapis/why are TK and THK alive.
Context:
After all the Void poofed, a benevolent entity/being (maybe a Higher Being?) visited TK and THK riiighhtt before they were gonna poof. (The thing talked to each of them separately) The being thingy talked to TK and THK and asked them whether or not they wanted to continue living in Hallownest or just poof. The being explained to each of them how they would do that (which is through Soulapis) since all Void has gone nonexistent, and all the properties of that (Soulapis). TK and THK decided to agree and so they're alive now.
(By the way, the mysterious being isn't malevolent, it literally told TK and THK all the ups and downs of the Soulapis which would help them live again. It is totally not evil!)
(Yeah I know the reasoning might be kinda bad but uhh I couldn't think of anything else without having complications in the plot and plot holes.)
6. New Kingdom(s?)?
Context:
I may or may not have made new kingdom(s?) for this Hollow Knight AU.
7. (It's time to talk about all the wonderful properties of) Soulapis!
Context:
Soulapis is name the strange being gave to the new sustenance that now fills the vessels (TK and THK). It has a heck lot of different properties to keep them alive. Here's a whole list of all the properties of this funky blue stuff! (Ignore some of the names, they're just there for fun)
1. Soulapis name origin: Soulapis is basically the color of ultramarine, which was originally made from lapis lazuli. Soulapis probably contains soul, hence the name.
2. Granting life to vessels: Currently, Soulapis has no known purposes or uses outside of all the ways it keeps TK and THK alive. So basically its only useful to those two.
3. A voice to cry out suffering: TK and THK can talk now (Or at least, project sound) thanks to this stuff. They still don't have vocal cords.
4. Nom nom: The vessels can eat now (by shoving pieces of food into their eyes, yes). Behind their eyes is a magic barrier (Thank Soulapis) that only let's food go through (unless the vessel doesn't wanna eat it). For example, if you were say, to throw a piece of stale raw broccoli (no offense to broccoli lovers), and somehow the stale broccoli made it into their eye, it'd just bounce off the barrier, (probably back into your face or the ground). If something makes it behind the barrier, it falls into the Soulapis in the vessel and the Soulapis absorbs any energy or nutrients from it. Leftover stuff is used to help repair and maintain the vessel's shell.
5. Stop stabbing yourself, THK: If the shell is injured, Soulapis helps heal it. Soulapis regenerates from existing Soulapis (this also means that eating could potentially speed up healing). If injuries in the shell go too deep, the vessel starts bleeding. Soulapis will dry and try to close the wounds (kinda like blood). However if the injury's too big it'll start bleeding badly. Soulapis is also thicker than water (also kinda like blood)
6. Expressions: Soulapis let's the vessels control the shape of their eyes (much like expressions).
7. Shrinkage: THK is really tall compared to TK and Hornet. Soulapis grants them the property of being able to shrink to a minimum of about TK and Hornet's combined height. They can also go back to their normal height (boss fight height). If THK loses too much Soulapis (about 4/5ish of their total amount of Soulapis) they shrink into their tiny form (Path of Pain cutscene) to recover and recoup. Eventually they'll be able to go back to their regular height and/or medium height (at around TK and Hornet's combined height)
8. A mind to think: Little (microscopic?) etchings in the insides of the vessel's heads help store memories and knowledge. The etchings are pretty strong but if the vessel whacks their head too hard they'll still get temporary amnesia. Temporary though because their Soulapis will help heal their head, also vessels can think.
9. Why don't you consider not breathing: Vessels don't need to breathe, but they can when they want too (manually). Technically this also means that they could scream, sing, or talk really fast for long periods of time because they don't need to breathe.
10. Extra stuff/notes: 1: Giving another Vessel a different Vessel's Soulapis is considered a bad idea, since sometimes it might have slightly different properties (i.e., how THK can shrink and TK can't [they're already pretty small]) 2: THK has two arms (in THK boss, he only uses one, presumably because they lost the other one after they got infected. Presumably, Soulapis or the strange being helped them regain it/regenerate it). 3: Vessels can detach changes in temperatures, Soulapis is mildly warm. Because of Soulapis's funkiness, Vessels (TK and THK) can survive at higher temperatures slightly better than regular bugs, they also don't like getting too cold. Soulapis's composition is a mystery.
That concludes the list.
Extra notes/formatting:
Regular text: Just part of the story
Italics: Characters' thoughts or emphasized words.
Bold: Mostly used for A/n's at the ends of chapters, potentially used for certain character's speech (e.g. a menacing character).
Bold+Italics: Used for extra notes in parentheses in A/n's
Underlined Bold: Used for emphasis in A/n's along with Italics.
A/N
That was way too many words (over 1700 total including every single word, even these) for the beginning's Author's notes, sorry about that.
I am attempting to try and write this in third-omniscient [like Dune style], so it might sound a bit like I'm head hopping.