That's true, but this isn't just talking about 5e, it's talking about specifically this game and this story, which is frankly, seperate from the system of 5e in terms of writing and characterization. It worked for Dark Urge because Durge was built from the beginning to be a character open for the player to alter as they wished. The dark urge as they exist in the past doesn't interact with the player so they can just not give specifics, unlike the companions who do interact and have very strong characters. Specifically making them more malleable would have been a mistake in a game that's already mushy and narrately incoherent.
