Leareth doesn't immediately know how to reply to that - he's very curious about 'Tar-Baphon' and the context there, but it feels like it would be a digression from the rather time-sensitive situation here - so he pauses.
- what does he actually need to learn, from this conversation? What information does he need from Iomedae to confirm that this isn't a trick, or at least reach enough confidence that he would be willing to approach her more directly?
If it's a trick, then someone - or Someone - engineered it, and that calls for an explanation. Leareth is actually having quite a lot of trouble thinking of one. It feels wildly unprecedented as a godplot; he wouldn't have thought the gods had the precision for it, to aim someone at him who could convincingly play the character of Iomedae as she's presenting herself. Vanyel has enough context on Leareth to know what kind of temptation would be called for to convince Leareth to take an uncharacteristic risk, but - he can't actually imagine what it would take to steer Vanyel into trying that, or the Heralds into cooperating with the deception.
He saw her artifacts, on the scry. He saw her impossible reflexes. And, more subtly than that, she speaks like someone of another world, with a different history and culture. Which is subjective, of course, but - his subjective sense is that it would be hard to fake.
If she's real, then the question is how she ended up here from another world, and why now.
...And how the gods are going to respond as soon as They figure out what's happening. He's quite worried about that.
(And even if Iomedae herself is real, and not originally a godplot, that doesn't mean she can't be made a pawn of one.)
:I do not currently consider myself at war with Valdemar: he sends, carefully. :I expect that they disagree, but - I had committed to not escalating this first even before I learned of your arrival. it would grieve me greatly to be steered into a war at this point, and I suspect that the gods seeing fit to force Valdemar's hand, now, means that They anticipated that if we had more time, we might have found an alternative.
I have no intentions of harming you. ...I am worried about your safety. I am also worried that our gods will be inclined to steer you into war with my people. I am not sure what assurances you would need, to be willing to relocate to one of my secure locations outside of the gods' territory, but - I am willing to offer that now.: