query: # fictional characters married to their siblings
  SELECT DISTINCT ?character ?characterLabel ?spouseLabel ?universeLabel WHERE {
    ?character wdt:P31/wdt:P279* wd:Q95074;
               wdt:P26|^wdt:P26 ?spouse;
               wdt:P3373|^wdt:P3373 ?spouse.
    OPTIONAL { ?character wdt:P1080 ?universe. }
    FILTER(STR(?character) < STR(?spouse))
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  ORDER BY ?universeLabel ?characterLabel