You know I could have just left it alone with my theory about Murata but the more I looked into that the more other stuff popped out related to the story we actually got.
Ok so to start there's a few ideas that are now proven wrong by this quest. In the beginning thanks to the teaser everybody believed that the Electro Yaksha was the one that became evil. (I actually used this justification to say he must be one of the dead yaksha because an evil yaksha would be too powerful of an enemy to leave running around on Teyvat. That was actually proven right. The evil one was definitely killed haha) We also had no idea who Bosacius was and some believed that it could have been the Geo Yaksha because the World Quest featured Geo enemies and mechanics. You guys have to know by now I thought Bosacius was the Pyro Yaksha, she went crazy out of fear for her life and she like Xiao were the only ones to survive but she disappeared on them. Over time she came to regret what she did so she created the World Quest to pay respects to her fallen friends minus Xiao since he's still alive and the Electro Yaksha because he betrayed them.
So what we know now is that Electro was pretty much all 3 of these ideas:
-He is Bosacius.
-He's the one that went insane.
-He's the one that created the World Quest area to pay respects to the Geo and Hydro Yaksha but not the Pyro Yaksha. (but we don't know why yet)
And I think that all played out in the quest based on Bosacius's hopes and desires. Remember at the end of the quest Xiao said Bosacius was just like the other 3 that they all thought they'd live in peace together after the fighting was done.
That never happened and it was probably a major regret of Bosacius who even after going crazy never forgot them. In fact they ended up being the only people he consistently remembered even forgetting himself and that he was a yaksha.
So now the quest. Who took part? Of course you have the survivor but you also have a Pyro allogene, Electro, Geo and Hydro don't you? Who were at odds? Geo and Hydro.
Side Note: Also many people thought that this
meant Bonanus killed Menogias. Looks like MiHoYo saw that and decided to give Menogias some justice.
Anyway even the genders match! Geo male, Hydro and Pyro female. Well almost. Kuki's not exactly a four armed big dude. (Maybe Bosacius had ideas? lol I mean people have been thinking he was a girl for over a year so lol)
This is point for point just like in the past. And Xiao was there for the ride. Only this time Pyro was very different wasn't she? Yanfei was one of the major reasons we got as far as we did. Meanwhile in the cutscene and teaser we saw that Indarias was pretty helpless.
It works either way: she could be helpless and couldn't do a thing to help the others from falling or she could have succumbed and actively caused their downfall before she was herself killed.
So Yanfei's participation could have been Bosacius's desire to see a different outcome where the group is unified and thanks to Indarias at that. Unlike them we ended this quest with Yanfei hanging out with Itto and Kuki.
This idea that all of this happened because of Bosacius works even better when you consider all of us were dragged into it by some kind of task. Yanfei got a will. (I'll get back to this.) Yelan was trying to investigate her ancestors because the Chasm was reopened. Itto and Kuki were looking for Yanfei. And finally Xiao decided to investigate the Chasm to find out which yaksha had gone missing down there. (Which is actually silly since the Artifacts talk about 4 arms and he's the only yaksha with 4 arms. Even without a name that description is a pretty big clue lol)
That actually brings up another point though doesn't it? Why were we there? I mean sure we had our own mission to look at what the Sky Nail hit when it stabbed the Ruin Serpent. But that's just like any of the reasons the others were there.
I think we're there to represent Zhongli. Remember the yaksha served and fought alongside the Geo Archon. All the enemies we faced in part 2 with the spherical Domain were Geo based and I theorized that was a form of penance by Bosacius. We were attacked by Geo enemies because he failed Morax. While the Traveler can have any element we resonate with Geo by going to Liyue and touching the statues. Also as Xiao said we're given special rights by Zhongli because he wants us to record Teyvat's history. (And I mean you know the prerendered cutscenes use Geo Traveler.)
So that brings me to actual Zhongli. He knew Xiao was going. He likely knew what was happening down there. He also likely knew we'd be trapped. I'd go so far as to say he saw everything that happened with his "Archon eyes" so he knew exactly the right time to be there to save his son. (He also denies it later on like it wasn't obvious what happened. Silly gramps.)
I think while this whole thing was Bosacius's consciousness reaching out and indirectly getting all of us to participate Zhongli knew the whole time what was happening. He probably wouldn't have consented to Xiao taking on the mission if he didn't realize this would both finally set Bosacius at peace and give Xiao some personal growth. And I say that because who's will did Yanfei follow anyway? As far as we know both brothers were incapacitated. Yelan didn't know what was going on and if she was going to investigate it it likely means nobody in her family knew either. Bosacius has noone left on the outside besides Xiao so even if it was his will who exactly left it in that book? From the Artifacts we know Bosacius himself arrived at the Chasm from the west so not exactly any spare time to pop over the harbor to do some reading.
What if it wasn't a "will" but a forgery? Where does Zhongli work again? Right the funeral parlor where they deal with the passing of people. Last wills and tes***ents and that kinda stuff. Isn't it just a little too coincidental that the will happened to be found in the middle of a book that pretty much describes what happened to Bosacius and Boyang down in the Chasm? And remember how helpful Yanfei was the whole quest. It's likely Zhongli manipulated Bosacius's desire just a little so that we got Yanfei and not some other Pyro like o I dunno Xiangling. Just imagine if it was Xiangling down there. Or Xinyan. We'd still be down there lol
Finally even their ranking might be a part of this. Remember how Bosacius paid respect to Bonanus and Menogias the Geo and Hydro Yaksha but not to Indarias. She's even omitted from that spherical Domain. Well the 5* characters we had here were Itto, Yelan and Xiao. Geo, Hydro, Anemo. Having gone crazy and running away he must have become very humbled by the time he died so Kuki is a 4* as is Yanfei.
So any brains I left unmelted? No? Ok I'll stop. 
Tips and Tricks from a Super Casual Genshin f2p
