A chat about the nature of oneiromancy in Vitubian metaphysics

Ohh, dreams, huh? Hmm dreams are already established to be a state of mind where one is closer to the supernatural, both IRL and in Vitubia, where information from the Heavenly Realm can be received through them. Then if you use chuubanite, perhaps you could manipulate your dream state to peek into someone else's dream by reading it from the Heavenly Realm. Kinda like a man-in-the-middle attack where you intercept the dreamer's transmissions to the Heavenly Realm.
If you were an advanced user, you could even perhaps create a magical construct that feels like the Heavenly Realm, and have the dreamer dream fully in a Realm under your control. With the analogy, that would be like tricking a client into connecting to your own fake server instead of the real server. Shit, is this how we get Netrunners into Vitubia? Or stuff like Inception.

The relation of the metaphysics system to dreams is very under-developed, so we're kind of treading new ground. But the QRD on it is that the Heavenly Realm can be seen a server, which serves magic to clients.
The clients take the form of chuubanite, and magic entities.
All beings have at least a tiny fraction of themselves in the Heavenly Realm; call it their soul if you want.
Since dreams have a precedent for being used to communicate things with the Heavenly Realm, I think it's fair to say a dream can be an opportunity for a Soul to connect to the Heavenly Realm.
The challenge when trying to share a dream with someone would be how to connect to their Soul. If the two Souls are separate, there is no way they could find one another in the immense Heavenly Realm.
So as you say, chuubanite (which can act as a client for the Heavenly Realm server) can be used here to connect the two dreaming Souls, essentially creating a Local Network which connects to the Heavenly Realm. I think that works well!

A possibility for sharing a dream at a distance: one of the dreamers would need to be infused with a lot of conceptual energy, so that once they connect to the Heavenly Realm, they emit a signal that can be picked up by another aware dreamer. That is perhaps how chuubas communicate divinations to their followers. In Vitubia, that might look like putting the dreamer in some kind of chuubanitic device (A dreaming throne?) or injecting them with a near lethal dose of chuubanite. There are parallels with /asp/otheosis.

For those two options, what you'd be doing would be sharing a dream, so you'd be able to exchange information on an even footing with other dreamers, perhaps use manipulation or gaslighting, but you'd have to play with the Heavenly Realm's rules. Forcing something on other dreamers would be a contest of willpower. If you had a more nefarious purpose and wanted to do more non-consensual things to the other dreamer, that's when you'd need to make the dreamer dream in your fake server that is under your control instead of the Heavenly Realm. That would be very high level chuubanitic oneiromancy though...

Does that mean the soul’s technically not part of you since that fraction of yourself’s in the Heavenly Realm and you dream to make the two in sync?

Interesting... I think your Soul and your being on Vitubia are always connected/in-sync, the dream is more like just something that makes it easier to communicate with it, perhaps because all physical distractions are tuned out. Maybe you can enter a dream-like state useful for divination with deep meditation. That would be more compatible with the concept of the janitors, who are beings that have a much larger fraction of their being in the Heavenly Realm, but can take conscious action on Vitubia.

if distant communications like that are allowed in this setting.

I think what came out of this topic is that it's allowed as long as it's impractical and inefficient enough to not provide a massive societal utility with current technology. For example, catalognauts are able to communicate at long distances through the catalog, but catalognauts are very few in numbers. So you'd want longer range dream sharing to be locked behind very expensive and rare circumstances/magical engineering.

I think they would need something. You need to tune your antenna to the right frequency to get a signal...
Well, taking the example of a Moriji priestess receiving a transmission from Mori, or a Sapling shaman divinating something from Fauna. It's straightforward to see that the respective divinators are tuned to their Goddess' "frequency" by using chuubanite of the respective type.
So, the "receiver" dreamer would need to use chuubanite of the exact same type as that used by the "emitter" dreamer. That would be like the frequency the dreamer is emitting on. Works nicely with conceptual energies being represented with waves.
The more precisely identical the receiver and emitter chuubanites are, the easier the communication would be, it would be like a better tuned radio and antenna, with less noise from other sources.
If the conditions above are fulfilled, I could see it happen accidentally.