Theory on one part of Dottore's experiment (spoilers)
Dottore opening up the false sky and trying to create a fourth moon is bound to piss off the Heavenly Principles, given the act of moon creation was something only Nibelung ever accomplished. Dottore cannot be blind to such a risk, but I think he *wants* to do that and see if it provokes a response from Celestia.
If it does, it satisfies his curiosity on what it would take to provoke the wrath of the gods. If it doesn't, it proves that either the Heavenly Principles are gone or that they're incapable of responding, which I'm sure the Tsaritsa would be interested in knowing (though I doubt the Doctor is doing it for her sake).
Both are bad outcomes, as with no HP to keep him in check, Dottore would basically have no higher power capable of stopping him, but him provoking the wrath of the gods could devastate Teyvat due to the HP's tendency for collateral damage.
Of course, I could be off the mark, but we'll only know for sure once Luna IV releases.
If it does, it satisfies his curiosity on what it would take to provoke the wrath of the gods. If it doesn't, it proves that either the Heavenly Principles are gone or that they're incapable of responding, which I'm sure the Tsaritsa would be interested in knowing (though I doubt the Doctor is doing it for her sake).
Both are bad outcomes, as with no HP to keep him in check, Dottore would basically have no higher power capable of stopping him, but him provoking the wrath of the gods could devastate Teyvat due to the HP's tendency for collateral damage.
Of course, I could be off the mark, but we'll only know for sure once Luna IV releases.
Commentaires
The events in Fontaine involving the prophecy and Neuvillete regaining the power of the Hydro Soveriegn along with the events of Capitano in Natlan is living proof that the Heavenly Principles is no longer active. And the Shades themselves stands divided as the only one that is actively trying to uphold the will of the Heavenly Principles is the Shade of Death. Istaroth, the Shade of Time, remains uninterested in the events that doesn't involve her domain. The Shade of Life is currently occupying the body of Rhinedottir who may be even more unruling than Dottore himself. And Asmoday, the Shade of Space, remains absent.
Now is the perfect time for Dottore to make his move. The Heavenly Principles is silent and the Shade of Space which directly involve with what he's doing, is nowhere to be seen. The Tsaritsa won't stop him since all the Tsaritsa wants is the Gnosis which he had already aquired two. One from Nahida and the other from Scaramouche. Not only that, it is in the Tsaritsa's favor for Dottore to unviel the false sky and stir up chaos across Teyvet against Celestia. And should Dottore really gain the power of the Moon Goddess, that will set his course straight against the Heavenly Principals and the Four Shades which makes it even better for the Tsaritsa. There is nobody to stop him that is stronger than him.
As for Dottore himself, I think he planned this for a very long time. He wanted the power of the gods to further his own ambition. Cause like everyone who knew him has said, he only cares about his experiments and nothing else. First, he orchestrated the events in Inazuma to obtain the vessel of a god which is Scaramouche. He then experimented on Scaramouche who gain the power of a god throught the Gnosis. Then, he use the knowledge he gain to experimented on Nodkrai to gather the power of the fallen Moon Goddess for himself. He's been waiting for this moment for a very long time.
And like Arlecchino have said, Dottore won't do anything against the Tsaritsa because he still need the resource that the Tsaritsa provides him. But given his selfish nature, Dottore probably wants to rid himself of relying on the Tsaritsa and gain the power to achieve his own ambition alone. And should he fail, that would only result in the death of one of his many segments. Not to mention that since his action is not directly against the Tsarista, even if he fails, he can still return to Snezhnaya. Practically speaking, the gain from this experiement exponentially out weighs that of the costs. It is too good of an oppurtinity to let go.
Moons might be smaller than planets but they are still quite large.
What is it going to take for those shades to do their job
When you watch the Luna IV trailer, he's still talking about experimentation. And I think what he wants to see here is whether it's possible to create a god, but also to kill him.
In the trailer about shadows, Interlude Teaser: The Gods Limit, Pierro says that when a human looks at a god, it can incur their wrath, which can lead to the destruction of a nation, but he doesn't care because he's already experienced it.
And then he wonders what happens when you kill a god. And I think that's what Dottore wants to find out because of his scientific curiosity. And for this experiment, he needs a god, so he decided to become one.
And the easiest way to do this with the means at his disposal is to use the Moons, which contain the principles of Life, Death, Time, Space, and Reason (i.e., the principles that govern Teyvat), giving him total control.
It is easy for him to recreate the Eternal Moon and the Iridescent Moon thanks to their marrow, but for the FrostMoon it is impossible because the Moon still exists and there is still a goddess, so he cannot take her place. That's why he creates a fourth one or opens up the sky to gain access to the FrostMoon and perhaps destroy it, which would mean killing Columbina to put his own moon in its place.
And I think the Tsarina knows everything Dottore is doing and agrees with it, which means she is willing to let her own nation be destroyed for her own benefit. It's the same thing when one of his fragments destroys an Irminsul tree.
Who's plan you ask? Hehehahahahaha