I don’t like any of them at all. They’re all so melodramatic and over-the-top special that it’s ridiculous. God I miss Edér.
All right, Shadowheart is ok. Eventually.
I kind of disagree to an extent. Actually in their world the only special one may be Shadowheart. Lazael is just a soldier. Wyll village boy whose home was destryed by Goblins (lol Goblin Slayer music intensifies). Astarion a vampire slave. Gale probably a mage who tried to take a shortcut to gain power and ended up the way he is. Shadowheart may actually be a favored by Shar. I do agree they all seem to be a little melodramatic at times, but I assume it's because of the ticking time bomb in their heads. As for OP question about Astarion. I don't use him in the party, but I do enjoy his overly flamboyant nature, and he seems to be more on the chill side of your entourage.