it is usually the DM's job to remind players on key things that their character know but they don't. a DC 5 or 10 religion check upon seeing shadowheart's circlet or armor followed by a brief resume of shar upon success feels appropriate, the same way we can get information about intellect devourers, the descent or what a soul coin is (it's definitely not a crypto currency).
if you don't want to have a dungeon master in your dungeons and dragons video game, there are many games out there but if you do, it's a bit more difficult to find so I am glad larian choose to do it and did it well.
I like the narrator, so I don't want my comment to come off as if I don't.
It's just that I don't think the narrator is enough in this case.
In storytelling, it's a matter of show, don't tell. Show the evil and danger of Shar worshipers, don't tell about them. It's more powerful to the player to actually see their evil in some way, as opposed to reading about it in a lore book or hearing the narrator say they're evil.
