Zahel and Shardblades (Spoilers)

[Fifth of Daybreak]

So I was thinking. Because Zahel has enough breath to sense life, can he sense life in Shardblades? Theoretically, the spren are still alive, just, as WoB stated, in a cycle of agony due to their consciousness being ripped out. So does he know the secret of the Shardblades being alive, or maybe even, can he hear the screams? I know there was also a WoB stating that Nighblood's nausea doesn't effect you if you've used him, so maybe that effect carried over and protects him from the screams? It feels like there's something missing here. 

[PorridgeBrick]

He probably senses life and spren by sensing their Investiture. It doesn't take much to realize that Shardblades are Invested, so he may not have thought beyond that.

[Fifth of Daybreak]

(Off topic, your name is fantastic PorridgeBrick)

That does make sense, but I would think he'd be very suspicious of any invested blade. He has also had a long time to reconcile them, which would be why he doesn't react now, but I'd love to read about his first interactions with them.