This is all considerably silly. Indeed, there is a convention that allows a citation of a quote to just the author without referencing the character. But doing so is informal and can be slightly unprofessional or grossly unethical depending on the context. The quote here is merely stylistic and so the decision to include additional information in the citation should just be based on whether or Yvain thinks it looks/flows better with the full cite. If Yvain wants to be more professional about it but keep the short cite he can footnote the full citation.

There. Done.