Ishar's spren experiment

[Wadders]

I was thinking about Ishar creating physical bodies for spren and it occured to me that this is effectively what happens to the heralds during the desolations.

The heralds at this point are cognitive shadows which are essentially a type of spren. They die in desolations, go to braize and eventually give up and return to Roshar. At some point in that they get new bodies, I am assuming that is a function or side effect of the oathpact.

So he seems to be trying to replicate what was done to himself and the other heralds. Perhaps Ishar is planning on breaking the last vestiges of the oathpact but wants to ensure that he can create new bodies for himself or others after that occurs. Or perhaps he is trying to find a way to create new heralds and is using the spren as test subjects.

[Quantus he/him]

As far as Im aware, that's the less horrifying option, yes.  The alternative is that it's realmically closer to the Fused where a Cognitive Being fully OverWrites an existing mortal's body, killing them in the process; that would mean each "subject" represented Two victims, one spren and one mortal (probably a corruption of the Radiant Bond that Forcefully Bonded the two way more closely together).

[BinarySecond]

I personally believe he's trying to force radiant bonds. Spren have to cross over to the physical realm when making a bond. If he can bring spren through, use his bondsmithing to force a nahel bond he's got unbound radiant - I assume he doesn't have many.

[Returned he/him]

Interesting! That might be exactly what he's after. Or maybe a variation on the same idea, like a way to exist primarily in the physical realm rather than being fundamentally of the cognitive, which seems to be the Heralds' current situation as cognitive shadows.

I'm still unsure, just because we know so little about Ishar, his condition, and his mind. His goals and actions may not even be coherent. I don't have any textual backup for it, but my intuition is that Ishar is looking for something bigger... something beyond the Rosharan conflict. Pulling things from other realms into the physical is a big deal and only happens in limited ways. Being able to do that at his own discretion would be an enormous deal, nearly Shard-level in implications and Cosmere-wide.