Tell him the truth. We've learned the geological landscape, gotten ourselves a foothold, and now are simply looking at the political landscape. Tell him we were debating/we've sent a caravn of goods to this very Stronghold, hopefuly to foster trade for materials we have little of.
Make it obvious we're looking for allies, but don't look weak. Be confident and tall, but amiable and not condescending. We have too many enemies right now and not enough friends, or even neutral parties.
After we're done speaking, maybe tossing about some orcs both as a sign of goodwill and minor show of power, we should head to Ceres and look at the local temples. Those should tell us more about the divine work there than the gods themselves could. Again, we should avoid treading on any toes. Imply we have a bit more power than we really do, but don't overdo it.
We ought to make ourselves something of an avatar as well. A spectral self that doesn't really do much but provide a face to look at for our priests.
Speaking of which, mark the Priest, Azula, and the other guy as our Triad. They'll be higher than high priests. I'm thinking a fairly basic system of Commoner<Priest<High Priest<Triad. Each level up will get a better boon, priests maybe having a minor one, High Priests being a bit more deadly, and the Triad being avatars of Life, Fire and Chaos. The Mages should be a separate faction, Civilian rather than religious in nature. After all, their powers don't come from us and forcing ourselves on them is bad.
Speaking of which, we should make it clear we don't force conversion. In fact, after we have a sizable enough power base we may encourage members of other faiths to join our communities. Mostly of our allies, of course, but allowing neutral gods followers homes in our town will make the whole community stronger.