Elaborate please on the third option 👀
Headcanon:
Both Khaenri'ah and Mondstat stand for freedom.
Often, when people refer to freedom, it's within a given constraint. In the simplest way possible, you may have the freedom to innovate a chair but you could never have the freedom to invent a chair because its already been done. You have thee freedom to do whatever you want in life so long as its within the given restraints of a society. On the other hand, you don't have the freedom to teleport halfway across the galaxy instantaneously because no one has granted you this freedom.
So while the purest form of freedom can never exist (a world in which you can truly do whatever you want, whenever you want it), there are some people in the world who are innately more free than others.
The power of a god, whether present or absent, grants different freedoms for different nations.
Khaenri'ah is a free nation without a god which represents the freedom to innovate, explore, and create.
Mondstat is a free nation with a god which represents the freedom to enjoy and indulge.
Khaenri'ah is limited in their ability to explore through knowledge due to Celestia while Mondstat (and all of Teyvat) are forced in a state of complicity due this restriction of knowledge, two sides of the same coin limited in two very different ways.
So why wouldn't Kaeya choose either?
















