question: What sibling of a character was influenced by M0 and M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ns:influence.influence_node.influenced_by M0 .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x1 .
  ?x1 a ns:fictional_universe.fictional_character .
  FILTER ( ?x0 != ?x1 )
  }