I also honestly don't understand the discussion about names, and even things like the characters' appearances. My feelings about them are completely based on such things as alignment and backstory. As a good-aligned character, how could I possibly be okay with a vampire spawn or a priestess of Shar?
Viconia was also a priestess of Shar and she was far from being evil.
But she *was* evil. Only extremely late in the saga, towards the very end of the second game, do you get presented with a possibility to have her character change. But that still means you have to have her in your party as an evil character for like 80% of the story-arc. I'm glad you brought up Viconia, though, because I always liked her character except for the evil part. So it has long irritated me that you can redeem her and turn her away from Shar only so very late in the second game, which in turn meant I could never have her in my always good-aligned parties. So if Shadowheart is meant to be the Viconia-equivalent in BG3, I really hope they allow you to effect a change in her alignment and away from Shar at a relatively early stage of the game. Getting her to change towards the end of the game would be completely pointless from a good-aligned party's standpoint.