I always saw Selune as a goddess for travelers. It is not explicit stated in the Wiki, but she is often worshipped by people, who travel a lot, the Gur people for example.
I always kinda saw the Gur as a mystic people with ties to lycanthropy. It makes sense to me and helps me understand where Shadowheart was coming from when she labeled Selune as "that moon witch." I thought that was such a fascinating way of describing her. Much more interesting and flavorful than accepting her as the light to Shar's darkness.
Come to think of it, I like a lot of what Shadowheart has to say about Shar early on. The way she comforts those who've experienced loss and helps them to act in the darkness. It gave me the impression that she encouraged those who were broken in some way, perhaps lost in depression and unable to face the day. With Shar they found the strength to act rather than to be lost in the paralysis of misery.
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Now I'm wondering if Helia was supposed to have had ties to the Gur people.