When English speakers try to make a text sound old (like in historical dramas), they for example use "thou" together with the "-st" verb ending.
What's the equivalent in Japanese, i.e. what kind of old fashioned grammar and vocabulary are used in works of historical fiction, irrespective of whether they are actually accurate?
What immediately comes to my mind is the use of が instead of の, as well as old-fashioned personal pronouns like [身]{み}. Furthermore, usage of ござる seems to be a characteristic of ninja-like speech.