Altarrin can read Bastran perfectly well. He's not surprised.
He had on some level vaguely hoped it wouldn't come up, maybe, but - he wasn't going to lie, or even steer away from it, he's– maybe this isn't and can't go the way he wishes this conversation could have gone, under better circumstances than these, but even so, it won't help to step even further away from the conversation he wishes they could be having instead of this one.
...He really should be honest that Alfirin still has the mind control up on him, even though this is inevitably going to give Bastran the wrong idea of what's happening here, because the reasons why he's comfortable with this and genuinely doesn't expect it to be abused are ones that might be literally impossible to convey accurately. He - settles on not bringing that up, Bastran is going to make the assumption anyway. And they really are on a deadline, here.
"Anyway. At some later point, in Iomedae's world, I read one of the other holy books of Aroden's church. The one that tells the history of his life, as a human wizard."
And he can give the summary of it, as he remembers reading it:
Aroden, as his histories tell it, was born before Earthfall in Azlant which only Axis, in these days, has perhaps surpassed, and He had become notable even before the Cataclysm as an extraordinary mage, brilliant and powerful, and then the alghollthu grew afraid of the human civilization on the surface, grew jealous, and they went to war, and they were, to their astonishment, losing. And they called in a great power from beyond the world, to destroy the humans, but they miscalculated, and very nearly destroyed the world.
Aroden survived, Aroden rebuilt civilization - not on Azlant's continent, which is just gone, a few isolated islands poking up above the sea, but on the alternate continent, devastated only by the indirect effects of the catastrophe (still sufficient to nearly extinguish humanity).
Aroden founded Taldor and worked to prevent the magical knowledge of ancient Azlantl from being forgotten forever, and he led an army into the Abyss and fought a demon lord, and he became a master of magic unparalleled in his world. And He travelled other worlds, looking for something, though He never told anyone what, and had spectacular adventures there, some recounted and some totally unknown.
And then, after hundreds of years of work, he dragged the Starstone out of the sea. It was a remnant of the moon that hit Golarion during Earthfall. It's said that it contained the essence of two gods, the ones killed when Earthfall happened.
Aroden set a series of elaborate precautions around it, and then ascended, and became a god. It is said He will return to usher in the Age of Glory.