He wasn't dead at that point, but he was certainly not in the best of shape. I do, however, agree that if Akka DID manage to save him, then he would have survived. Or died a better death--in AKKA's arms, but that would make literary sense and I guess we can't have that in the Bakkerverse.
Mercy!? HAH! It's bullshit! If he REALLY wanted Proyas to be spared of hell, then he would have handed him over to Achamian and/or done whatever it took to ensure his survival even if it mean ending up like Malowabi, but NOOO! Proyas was chattel to Kellhus and he would rather destroy Proyas than let someone else have him. And the morale thing? I think that's BS too.
It STILL bothers me too and I STILL get angry thinking about it. I firmly believe that Proyas's fate served no purpose except to be subversive for the sake of being subversive. There were so many possibilities and expectations (at least on my end) raised for him and ALL of them were subverted/averted. Like, WOW.
"I figured there would be an ultimate point to Proyas, that he was being conditioned to serve as N. Cauytas or whatever (engine for the NG that Kellhus would then yoke). As it is, it's both horrible and somewhat underwhelming, like most of TUC."
Yea, pretty much this. I honestly thought so too. I also thought a whole lot of things, including Kelmomas being the battery with Proyas being the "Unholy Steersman" after being the one to salt Kellhus. because why not? He was betrayed by Kellhus. Might as well become literally part of the Consult >:(