Firstly, I like these companions a lot so far. But I do want to say as someone who knows basically nothing about D&D lore, is it actually obvious that Shadowheart is a cultist of Shar when you meet her? I only know because of out of game info and in the context of the story that feels like something we wouldn't have reason to suspect initially. Same with Asterion; we're definitely not supposed to realize he's a vampire spawn and the fact he can walk around in the daylight takes away a big reason why you'd ever be suspicious of him on that front. The fact he tries to kill you when you first meet him on the other hand? That's more problematic I grant you.