I really like how this game handled evil cults.
Mostly just how the ran the spectrum of follower types. You had your "divine warlock pact" like what Ketheric and Gortash had with Myrkul and Bane respectively. But you also had the true believers like Shadowheart and the priestesses of Umberlee. People who genuinely believe they're on the right side of history thanks to a healthy mix of gaslighting, mental gymnastics and indoctrination. I especially like how the Umberlee priestesses could practice in broad daylight in Baldur's Gate which made perfect because no harbor city wants to be on the bad side of the Bitch-Queen.
I think every good fantasy story needs a variety of different types of evil cultists.