The Last Hero (2001)

Cohen and his elderly companions have spent a lifetime doing what barbarian heroes are supposed to do, and are increasingly annoyed by the world that has followed. Their final grand gesture turns accumulated experience into both a formidable resource and a problem for everybody else. Pratchett's illustrated adventure can be very funny about ageing without treating time as harmless. Familiarity with Discworld helps the cameos land, though the old heroes' grievance is easy to recognise.