One of the biggest mysteries in Genshin Impact is the Fake Sky theory. You can find out here how it connects to the twins, and what it has to do with the true nature of the world.
One of the biggest of Teyvat's mysteries is the Fake Sky theory brought up by the Wanderer. It flipped our knowledge about the world quite literally upside down. What did Scaramouche mean when he talked about this, and is the real sky truly in the abyss?
Genshin Impact: Are People In Teyvat Living Under A False Sky?
The stars, the sky... it's all a gigantic hoax. A lie. – the Wanderer
Back in 2020, closely after Genshin Impact first came out, Wanderer, who was called Scaramouche back then, has said this legendary quote in the limited timed "Where Ancient Stars Align" Quest.
The idea is that there is a parallel world, upside down from the one we travel in, that is facing the true sky. That means that the Abyss, and with it the root of all knowledge and leylines, Irminsul, are actually turned around the right way. Most people in Teyvat aren't aware of this, so many very confusing conversations can be excused that way. Tighnari once claimed that Irminsul is growing downwards rather than upwards, and of course he'd think that when he doesn't realize that he was the one who was upside down all along.
Fake Sky. This is what Scaramouche meant | Teyvat Dome World Model by u/hyperiongames in Genshin_Impact
Many of the fallen civilizations that were famous for spiting the gods had one thing in common – being built underground, aka being further away from Celestia's controlling gaze and closer to the actual sky. Examples of these include some of King Deshret's buildings, the chasm and the entirety of the civilization of Khaenri'ah and Enkanomiya. It seems like every region has had some type of connection to the underground.
P.o.V: Me thinking about how great Genshin is.
A personal theory that I'd like to make at this point is that we might have had the real sky in front of our noses the entire time. Just think about it, whenever you open the map, there is a celestial screen behind all the unexplored areas – seeing where I am going with this? It would certainly be funny if this was the real sky, especially considering that we as players have almost an authorial, upper perspective of the world. We truly are alienated from it.
Celestia has been spotted by players to come closer and closer with every version, it is coming towards us simultaneous to the traveler advancing in his journey. What this means can only be speculated, especially if the sky is really fabricated. Is that a warning by celestia? And to whom, the traveler, his sibling, the Fatui for stealing gnosises left and right? Whatever it is, I don't think Celestia is happy with the direction of independence the human race is going towards. We have seen what it is capable of with Khaenri'ah, and there is a pretty decent chance we could see something like it again.
And wouldn't it be fun, with all the contrasting counterpart symbolism we see in Teyvat, where Teyvat symbolized Lightness and the Abyss Darkness, the one side delusion and the other truth, if the twins were separated so they both can come together to reveal the true nature of this world together? (See what I did there?)
The Doctor: "Let me ask you... Have you in all your mighty knowledge ever heard the rumor that "the skies of Teyvat are fake"Nahida: "...Huh?"The Doctor: "That's the secret hidden by Irminsul concerning the "truth" of this world..."