^ It highly decreases the likelihood of aliens, let's put it that way. But if they do B5 like that, it kind of kills the show, since obviously you can't have 'First One'-like characters if there are no aliens. Races like the Centauri, Narn, etc. didn't have a lot of spectacular abilities, but you can't take Vorlons or Shadows and make them into human variants. Races like that are just too powerful and would require way too much rewriting.