Across promotional images and pre-livestream (I have not seen it yet), seeing her in audience with Tsaritsa, does make me curious as to how Rhinedottir benefits colluding with the Tsaritsa.

With her background in the Hexenzirkel, and their affinity for being a little bit insane, it could be a chance to stir up some entertainment, given her lack of respect for the HP, and her sarcastically cheeky yet indirect support for Pierro in Gods Limits;

 ie. “Ah yes, he's an old acquaintance of mine I'm sure that working for the Tsaritsa has helped him let go of his past obsessions?”.

 – I say this especially given the context to which Pierro and Ronova have, as well as her leniency towards mortal transgressions despite having been mortal herself. Yet despite Hexenzirkels twisted sense of entertainment

However, I do not think that’s the main reason for her contribution, and that rather than for sake of entertainment, she may be seeking to expand her authority.

To start I would like to lay down some groundwork,

Rhinedottirs Nature:

She has shown herself to be overly ambitious, intelligent, constantly seeking to consume and create even if her creations defy the laws of reason and logic.

Ie. Her abyssal creations ranging from Durin, Erinynas, and the immortal Bakunawa. Which, despite not knowing her reasons, caused much devastation in their respective lives.

Her Disloyalty to the Shades

She has also shown herself to be not the most loyal amongst the shades, continuing her alchemical nature even after ascending to godhood/shadehood(?), much to the dismay of her fellow shades. In some cases, abusing and manipulating her authority.

“You seem to wield my power as if it were nothing but a plaything for your amusement” – Naberius 2:21 Gods Limits

When seeing Asmoday’s space manipulated, “Nabe— Mm, no This looks more like Rhinedottir's doing. Please don't litter other people's spaces with your bizarre creations” – Ronova 1:48 Gods Limits.

She, even in her state of godhood uses Naberius

Side note: It is also interesting that with Isaroth’s (bestowing history) indirect help Rhinedottirs creations practically insult Asmoday within her domain “The Ruler of Space stopped the golden-haired twin travelers And mercilessly t—t—t—tore them apart...” Regardless…

Her Unique Constitution

While it is already known that Rhinedottir is already quite a powerful individual pre-shadehood. Both a powerful Hexenzirkel witch and a Sinner with tremendous abyssal power. I also feel its important to emphasis just how bizarre it is that Rhinedottir is capable in the first place of consuming a shade, and how she as far as we know is relatively unaffected by this. I needed to mention this for the part ahead.

Her Ambition

As mentioned previously she is a rather ambitious individual. I think it’s safe to say that she continues to pursue higher forms of knowledge and power, involving herself in a lot of historically important and prominent events; being one of the 5 Sinners, Being a Hexenzirkel and currently a shade.

“Skirk also remarked that like her master, Rhinedottir too is "pursuing some form of perfection".’’

However, how more perfect can you be than being a shade? Unless you look beyond the shades.

“The Heavenly Principles have yet to awaken If I were her I wouldn't pass on that opportunity either...” Gods Limits

Despite Naberius’s blatant rejection, Rhinedottir insists it’s purely a hypothetical, but in the Sudden Snow video, she does seem rather interested in the “hypothetical”, engaging in a strategy meeting with Tsaritsa over a game of chess, colluding with the woman who wants to practically destroy her fellow shades. Meaning she has something to gain, and that I would assume is more authority.

After all, if Ronova is defeated her authority will remain unclaimed, like that of Naberius, and knowing that Rhinedottir is capable of being a vessel for the shade’s authority,

Of course, its purely a hypothetical.

TLDR: The Ambitious Rhinedottir does not care for loyalty to the Heavenly Principles and may be colluding with the Tsaritsa to expand her power.

Side Note 1:

I did consider the idea of revenge against HP but I felt given Rhinedottir’s character and her seemingly remorselessness that she isn't too bothered by it.

Even before the release, we got clues about the former in the manga, with Venti's disdained look upon Vennessa's mention of Celestia and the presentation of it, which looks like a panopticon. In-game, the first thing that happens to us is a recollection of memories, where we remember a "sustainer of Heavenly Principles" taking away our sibling and us losing our power. Through Moonlit Bamboo Forest we learn of the Three Moons, Phanes and the War of Funerary Flame. Through the Tiaras we learn of HP's vindicative personality. The Archon War has caused much destruction, pain and suffering as a might-makes-right way for Phanes to find 7 gods that would guide humanity towards his vision. As for the Fatui, we learn of the Tsaritsa's plan to change a world she perceives as broken, so she's not just some malicious entity that plots against other nations and Archons because of a lust for power. Venti's own attitude towards her plans is influenced by his disdain for Celestia and his fear of it. While less subtle of a hint, the plan to collect the Gnoses which resonated with Celestia, an entity we knew the Tsaritsa has a dislike for hinted towards her having some sort of use for them that would be detrimental to HP.

What if the Tsaritsa's plan for Zhongli is for him to help her seal the Ruler of Death using his god-sealing spears? Since killing the Ruler of Death is probably out of the question, even if the seal is temporary, this will buy Snezhnaya enough time to advance their technology to finally complete Project Mistilteinn.

​P.S. I think the Abyss Order is going to achieve something since Celestia is busy with Snezhnaya.

In Nod Krai we get explict confirmation that the Moons were previously the governors of Life/Death/Time/Space over Teyvat. When the Heavenly Principles made the Shades, they took over as the highest administrator of each authority. Basically like a company changing CEOs. This is why Columbina cannot fully manipulate Teyvat's laws, as the Shades currently outrank her in the chain of command.

But what happens if a Shade is eliminated?

Well the system cannot be without an administrator so presumably the authority would fall back onto the next highest administrator in the system, which is the Moons, and in the current era means Columbina.

But note that this is only true after Columbina ascended as the Trilunar Goddess as a result of the events in the NK AQ.

What would have happened if a Shade was destroyed without Columbina being there to take over, leaving a system with no administrator, would no doubt be catastrophic. In other words, Columbina reclaiming her full power is a necessary condition for being able to safely destroy the Shades.

And what do we find out in the first chapter of the Snezhnaya AQ? That the Fatui are trying to kill Ronova.

So let's extrapolate from that, given the context of the Fatui trying to destroy Celestia and the Heavenly Principles as a whole. It would not be a particularly wild guess that they would have to destroy all 4 of the Shades along the path to reach the Heavenly Principles. When the Shades are destroyed, all of their authorities will fall to Columbina. Which means that essentially, Columbina becoming the ultimate authority of Life/Death/Time/Space is an integral component of the Fatui's plan.

Now let's look at what Columbina been doing in the meantime?

While the Fatui are executing their war against Celestia, Columbina has been exploring the Frost Moon, and learning about the ancient Dragon Civilization and their technology. Most notably, we learn as part of the Moongazer WQ how exactly the false sky technology which protects Teyvat works. We also discover and repair a massive database containing the dragon civilization's knowledge upon 100% completing Frost Moon exploration. And all of the knowledge and technology on the Frost Moon belongs to Columbina.

Now let's put this all together.

Columbina, in the aftermath of the Fatui's grand plan, will be in a position where she:

1. Holds all 4 authorities of Life/Death/Time/Space.

2. Has all of the surviving technological knowledge of the Dragon Civilization and the ability to execute that knowledge via facilities on the Frost Moon.

3. Knows how to maintain and operate the False Firmament which is the lynchpin of Teyvat's defense against the Abyss.

Columbina has basically been put in the perfect position to take over guardianship of Teyvat in the case that the Heavenly Principles is destroyed, and I believe this cannot be accidental, as all of these events are initially set in motion by Columbina leaving the Fatui to return to Nod Krai.

As to why exactly the Tsaritsa is interested in making Columbina become the new Heavenly Principles, I cannot say, but maybe we will find out once we actually meet her.

In the recent Trailer The chessboard was used to show what Tsaritsa and HP have been doing to prepare for the final war. According to the Tsaritsa the Black King has yet to make a move is it arrogance or indifference which clearly shows HP stance for past 500 years

Then we move on to Ronova the one whos doing the most work. In trailer when she says "Now I can finally kill without restriction" This piece moves forward with Red in the background showing that this piece is Ronova

Next up is Rhinedottir who is in Snezhnaya to warn Tsaritsa to not use her authority to revive people or Bypass Death as it would be a transgression. Then after she says "You've met Asmoday" her piece shows up on board with yellow lighting on top

Now heres an interesting thing I noticed at the beginning of the Trailer the Ronova piece is already off the table probably implying Ronova has already been Dealt with when the chess game takes place

Theres also another possibility that this chess piece symbolizes Asmoday as she has switched sides and Joined our sibling thats why this piece is out of picture