question: Which character that M1 was written by and edited by was M2 's editor
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:fictional_universe.fictional_character .
  ?x0 ns:film.editor.film M1 .
  ?x0 ns:film.editor.film M2 .
  ?x0 ns:film.writer.film M1
  }