Geralt seems pretty clearly in the 'not-a-game-original' category to me.
The character that sits in the closest thing to a grey area to me is Aya Brea since the Parasite Eve games technically serve as a sequel to the novel, but have an unrelated cast, location, etc. They basically just go "Oh yeah, that stuff happened too, I guess" with respect to the novel's scenario, then do their own thing.
Well, and I guess like... Suikoden. Would the adaptation be loose enough that it's considered a separate entity from the novel? Not really plussed either way, granted.
Post-pass could consist of nothing but Capcom characters and I would be happy as a pig in ****.
Replace Capcom with SEGA, and that's my sentiment.