Epileptic Trees / Genshin Impact

• There are invisible walls that prevent players from exploring unreleased regions, accompanied by the screen darkening while Paimon appears and encourages you to turn around, saying "Let's explore the area in front of us later." An interpretation/joke/fan theory on this matter suggests that Paimon is actually using some space-manipulation power to force you in turning around.
• Alice is Klee's mom, but she entrusted her child to the Knights of Favonius and went off somewhere, causing Jean to step in the role as Klee's adoptive mother. However, fan theories (which also involve shipping) suggest that Klee might be the biological child of Jean (on the basis that Klee is also blonde just like her) and Diluc (on the basis that both of them have the same eye color and are also Pyro-elementals). Note that Klee has elf-like pointy ears, a trait that doesn't apply to Jean or Diluc.
• A popular explanation for the three identical Katherynes in the Adventurer's guild booths is that they're Ridiculously Human Robots. They do occasionally say "Error" and "Rebooting" when you're not talking to them. Furthermore, fans also theorize that they may have been built by Snezhnayans (as the Fatui wield technology that isn't seen in the available regions, and the Adventurer's Guild HQ is mentioned to be in Snezhnaya). Also, the Fatui Harbinger Sandrone/Marionette wears a maid uniform under her coat that's very similar to Katheryne's uniform, suggesting that she's the one who built them to begin with. This was eventually confirmed in Chapter III, where Nahida refers to Katheryne as a "bionic puppet".
• Dainsleif is thought to be Fischl's brother simply because they look similar to each other. Both of them are blonde, have eyepatches, and wear clothes with dark-blue/purple themes. However, Fischl's bio doesn't mention her having any older brother at all. The fact that he's actually over 500 years old and the last sane survivor of Khaenri'ah means that he can't possibly be her actual brother - though her Chuunibyou personality's backstory seems to imply their could be some other connection to him instead.
• There's also theories floating around about Dainsleif being an older Aether, the male protagonist, from the bad future or an alternate timeline in which he failed to save Lumine due to what is presumed to be his monologue from the "Teyvat Chapter Storyline Preview: Travail" trailer. The "brother prince" from the "Gnostic Chorus" trailer is also often presumed to be either him, or the Traveler.
• Because the finale of the "Teyvat Chapter Storyline Preview" trailer has Dainsleif mentioning "show me you are worthier than I to rescue her" to Aether, a common fan theory suggests that he is referring to Lumine and might have known her for a long time before Aether woke up in Teyvat (since in this context, Aether wants to find her sister in the first place). This line alone also opens an implication that Dainsleif is closely or romantically related to the missing twin, so a bizarre fan theory then asks a scenario: What if we are playing as Lumine, and Aether is the missing twin, would Dainsleif have feelings for Aether? Dainsleif world quest released in the 1.3 update partially confirms this via Sliding Scale of Gameplay and Story Integration where he'll refer to the playable twin as being similar to the non-playable twin.
• Ever since this image◊ popped up, a fan theory regarding Sucrose suggests that she might be an Electro Fatui Cicin Mage since the latter's model has the same hair style and color. Some players then hoped that Sucrose would receive a Fatui outfit, while others began calling the Cicin Mage enemies "Sucrose Alter". Supposedly she has an Electro Delusion along with her Anemo Vision, allowing her to control two elements; though our first encounter with a Delusion is Childe's boss fight, who is much more powerful than a Cicin Mage. Nothing in Sucrose's playable version indicates she has hidden evil powers, though it's conceivable that could be left for a future update.
• Honkai Impact 3rd fans who play this game made several theories on how both games are exactly related. Beyond Otto Apocalypse's observation of the Imaginary Tree showing a cameo of Dvalin, and the concept of a Multiverse from HI3), some fan theories try to predict the story of this game based on events that happened in Honkai Impact 3rd. Others try to guess if a Genshin character is an Expy of a Honkai character even if their similarities may not be obvious at first glance. For example, some fans think that Zhongli may have been based on the characterization of Fu Hua^note Being very old, knowledgeable, wise and powerful individuals who worked as "guardians" of their own lands (Shenzhou/Liyue), having taken on multiple identities throughout their long lives, and having problems with their memories being "too good". but with the body of "Post-Honkai Odyssey"'s Protagonist^note A story that takes place years after the "end" of Honkai's threat on Earth. Some fan artists even depict both characters together out of Commonality Connection, with Fu Hua's Azure Empyrea appearance being chosen to match Zhongli's aesthetics.
• Vennessa, the founder of the Knights of Favonius, is commonly theorized to be Diluc's ancestor (and thus making him a part Muratan) due to his red hair and Pyro Vision, and the falcon that appears in his Idle Animation is commonly thought to be her in falcon form. This usually ignores the lore where the Ragnvindr clan has always been red-haired and had existed long before Vennessa came into Mondstadt.
• The Tsaritsa is, as of this writing, the only Archon whose "divine ideal" is not explicitly confirmed yet. In the "Travail" video, Dainsleif mentions the kind of gods each Archon is supposed to be, but of Tsaritsa, he only says "she's a god who has no love left for her people". From this, many fans speculate and guess that she is (or was) the "God of Love." It's also suspected she might be an Expy of Bronya Zaychik from Honkai Impact 3rd as both of them are associated with Russia and ice.
• Despite being a fictional character, many fans have latched onto the idea that Ms. Hina may be added into the game someday by using Albedo's alchemy to bring her to life.
• There are widespread theories that Kokomi is a Vishap having taken human form, or even the reincarnation of the Primordial Dragon of Water due to her odd eyes matching the claim that Vishaps gradually lose the ability to see as they age, the belief in-universe that the Priestesses of Watatsumi somehow descended from Vishaps, and Kokomi's constellation name, Dracaena Somnolenta, translating to "sleeping dragon". Patch 2.5 even introduced the in-universe theory that Vishap-People have infiltrated human society. That Kokomi denies the existence of Vishap-People in the same patch did absolutely nothing to discredit the theory.
• The Aranara Ararycan is theorised to be related to Dottore due to him being the only blue Aranara (all others are green, orange, yellow or brown), the pattern on the leaves on his head looking vaguely like a Fatui insignia and the world quest focused on him being about the Ruin Golem of Devantaka Mountain (where notes left by Dottore, as Zandik, back when he was in the Akademiya can be found).
• Before Alhaitham's playable release, it was common for fans to speculate that Alhaitham was a reincarnation of the King Deshret. In the eyes of fans, this was "supported" by Alhaitham's supposedly unnatural looks, primarily his Exotic Eye Designs that resembled the symbol of King Deshret, his shirt having the symbol of the King Deshret on it, the gem on his chest having the same shape as the gem that symbolically depicted Deshret in Kasala's memories, as well as the story's suspicious insistence that he's just some guy that wants to live a peaceful life despite the competence he shows and the lengths he'll go to the achieve his goal. Come Alhaitham's playable release which went into depth about his background, it was confirmed that he really is just some overly competent guy who worked hard during the Archon Quest so he could continue to live listlessly and not related to King Deshret at all.
• Another prevalent theory concerning Alhaitham was that he was an android due to his distinct headgear connected to a cord extending down his back. It turned out to be a pair of noise-canceling headphones connected to a music player in his waist wrap, both of which he invented.
• The extraordinary lack of information regarding Natlan compared to other regions (including the total absence of NPCs from there) has led to lots of speculation on the reason behind it, for example, it being in a state of self-imposed isolation. There are even theories about the region having already been destroyed (usually by Celestia or during the Cataclysm), although they're seemingly contradicted by this tweet from the game's Spanish Twitter account celebrating what appears to be the Day of the Dead.
• Out of Celestia's "Primordial One" and their four shades, only Istaroth's divine authority of Time has been explicitly named. However, among the five different types of artifacts is the timepiece, the Sands of Eon, leading players to speculate that the other authorities are likewise represented by the remaining artifacts, with the Circlet representing Reason, the Goblet representing Space^note Dubbed in Chinese as the "Cup of Space/Emptiness/Void", which is curiously the same wording used for the Herrscher of the Void that the Sustainer of Heavenly Principles heavily resembles, the Flower representing Life, and the Plume representing Death. This theory gained more traction after Rene's research into Descenders speculates that they are distinguished by their power of Reason. More notes from the World Quest also muse that by becoming a Descender, he would become "one that can protect the world, sustain the world, destroy the world, and create the world".
• That Scaramouche appears in "The Song Burning in the Embers" animated short has led some to theorize that Arlecchino somehow remembers him — despite his existence as a member of the Fatui being erased in Irminsul — and that the short is from her memories and not a depiction of what actually happened. As such, this could mean that she and those with the Crimson Moon bloodline are Descenders or at least descended from one.