Where the Heart of Anti-Shurtugal Rises Again.

Characters being created out of necessity isn't a bad thing. It's just bad when characters are only their necessity and nothing else. Rhunon is massively better than the other two examples as she's introduced way earlier than when she comes to be necessary and actually feels like a part of the world, providing lore and diversity to the store. Barst, knife guy and Varug were just pulled out of Paolini's ass and added nothing but their very strict necessity (and I use necessity very lightly in the case of knife guy).