Lae'zels and Jaheiras introductions are my favourites actually, because they are not friendly, but extremely practical. Lae'zel would never had even talked to us in a different situation, but she knows, she needs help and is honest enough to take it. And Jaheira was never someone beating around bushes, so that fits.
What I do like about both Lae'zel and Karlach is, that they are totally honest from the beginning. It's refreshing, since that is not do often the case with videogame companions and the others are not so forthcoming. Well the non origins are, but for them, there is no reason to lie. I'd probably not want to tell complete strangers, that I worship one of the most evil goddesses, being a vampire, having to consume magic or turn into an atomic bomb or being a fiendlock. Minthara and Halsin are already known to the group when we get them, though I did thought, we would find out, that Haldin is a werebear tbh, since he doesn't seem to have his bearshape under control, when even a level 2 druid can do that, and they scratched the werewolf origin.