After playing a few sessions I would agree that Vaesen leaves a good amount of the heavy lifting up to the GM. Castle Gyllencreutz is a flavorful addition that definitely inspires to be used in some way beyond the mechanical bonuses it provides. But the book doesn’t really give any specific guidance on how to do that. It’s open-ended and that comes with a reliance on a strong narrative and player buy-in to carry the game. I enjoy these types of systems personally, but it’s something to consider if you’re looking to bring it to your own table.