Oathgate spren, why 2

[Sythrin]

Why are there 2 spren for the oathgate? Quite the singularity except if I remember correctly soulcasters.

Is one perhaps responsible for transportation across 1 realm, while the other between realms?

Like if you kill one with antiloght. Could the other only transport them across shadesmar and physical realm? But not across oathgates?

Maybe in future we will see a lonely oathgate spren that moved away from Roshar and now does business as easy transportation across the realms?

[Qviqve]

In my mind they work like a pairing fabrial: Half of the Inkspren is in Urithiru and the other half in whatever Oathgate in Roshar so they can teleport people between them. One pair for going one way and the other one for comming back.

However it is interesting the point you make here!

59 minutes ago, Sythrin said:

Is one perhaps responsible for transportation across 1 realm, while the other between realms?

It could be the same principle of the pairing fabrial: one pair horizontal (for in ream transportation) and the other one vertical (intra-realms transportation).

[Treamayne]

1 hour ago, Sythrin said:

Why are there 2 spren for the oathgate? Quite the singularity except if I remember correctly soulcasters.

Is one perhaps responsible for transportation across 1 realm, while the other between realms?

Like if you kill one with antiloght. Could the other only transport them across shadesmar and physical realm? But not across oathgates?

Maybe in future we will see a lonely oathgate spren that moved away from Roshar and now does business as easy transportation across the realms?

We may get more information in SA5, but for now the only WoB close to the matter is:

Spoiler

Questioner

The spren on the other side of the Oathgate in Shadesmar... One is an inkspren-- I am guessing, no? Because there are two spren that grant the Transportation Surge so that would make the other a Willshaper spren?

Brandon Sanderson

RAFO.

Oathbringer release party (Nov. 13, 2017)

It seems important to me that one each is described as Black and White. From Ivory and Blended we know the Inkspren are black with iridescent oil-like tones. So the other would either have to be a different Spren, or an Inksren that was changed, somehow. Likely they control different functions, but I doubt it would be like Paired fabrials because:

1. Those are a recent developement
2. The Oathgates do not only go to/from Urithuru - that's why the mosaics exist to select destination. Radiants can transfer between any two of the eleven locations 

Hope that helps

[+Child of Hodor]

They need to do the secret handshake of Transportation in order for it to work. 

[Sythrin]

59 minutes ago, Treamayne said:

Those are a recent developement

But just because they are recent developed technologies. It does not mean the concepts are new.

this pairing element could be already existing in the nature of the cosmere and was then developed.

other examples would be the spirits of Yumi and painter.
For one the lines, are made of 2 different colors and the spirits Yumi summons can manifest as 2 paired objects.

So probably Spren could even split themselfs to create multible parts of one object.

[Treamayne]

10 minutes ago, Sythrin said:

this pairing element could be already existing in the nature of the cosmere and was then developed.

I was specifically refering to the version used by Spanreads, splitting a spren into two parts - which we know from The Sibling's reaction is bordering blasphemy (and therefore not likely to be the mechanic here)

10 minutes ago, Sythrin said:

For one the lines, are made of 2 different colors and the spirits Yumi summons can manifest as 2 paired objects.

This may be closer to the mechanic, but while these are "paired" they are not paired in the way current rosharan fabrials are (such as the Ch 4 Farming tool)

Spoiler

 As always, the spirit split into two to make the devices—in this case a machine with great insectile wings, and a handheld device to control it from the ground.

And we do not yet know if this time of split spirit Fabrial does or can apply to spren. I would agree that if this is a realmatic principal, then it is more likely to apply to spren - if it was due to that Shard's nature, then less likely it would apply to spren. 

[alder24]

3 hours ago, Sythrin said:

Why are there 2 spren for the oathgate? Quite the singularity except if I remember correctly soulcasters.

Is one perhaps responsible for transportation across 1 realm, while the other between realms?

Like if you kill one with antiloght. Could the other only transport them across shadesmar and physical realm? But not across oathgates?

Maybe in future we will see a lonely oathgate spren that moved away from Roshar and now does business as easy transportation across the realms?

I think that's because Oathgates are conjoined fabrials (but not made like modern ones by splitting spren in half). Each gate is a separate fabrial, manifested from one spren, but two gates are paired with each other. Each gate in Urithiru is paired with one gate somewhere else. Because of this pairing, two spren of both fabrials always manifest at every Oathgate, but they are the same spren for every pair of Oathgates.