Original sentence: According to a convention of modern fantasy, the 'v' in elven or elvish refers to human-sized elves (who correspond more closely to the mythology of the old Germanic mythology), whereas the f in elfin or elfish refers to tiny-sized elfs (who correspond more closely to the folklore of the Renaissance and Romantic Eras)
Edited sentence: According to a convention of modern fantasy, the 'v' in elven or elvish refers to human-sized elves (who correspond more closely to the mythology of the Viking Age), whereas the f in elfin or elfish refers to tiny-sized elfs (who correspond more closely to the folklore of the Renaissance and Romantic Eras)