question: Who influenced a character that was influenced by M4 and was influenced by M1 and M2
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:influence.influence_node.influenced ?x1 .
  ?x0 ns:influence.influence_node.influenced_by M1 .
  ?x0 ns:influence.influence_node.influenced_by M2 .
  ?x1 a ns:fictional_universe.fictional_character .
  ?x1 ns:influence.influence_node.influenced_by M4
  }