It depends on how broadly you define 'someone' or a person. If you would say that all things that have souls are persons then the dream character that appear in your dreams isn't a persons.

Of LW the consensus is that there are no souls and therefore that's no criteria by which you can decide whether an entity is a person. Another straightforward way to define person is to define it as those entities with ownership of a physical brain. That definition works for a lot of cases but breaks down if you want to see uploaded brains as persons.

It corresponds to the discussion whether animals should be considered as persons. We agree that it's bad to torture animals but that it's not as bad as torturing humans.

Dream character could have a similar status as animals. The kind of entity you conjure up when you think about torturing another person are probably a bit less of a person than a dream character but there not necessarily 0% person.