Louis calling himself a "magical negro" to Morgan and then turning away and not helping either him or Emilia later was very loaded.
I don't know if Morgan really sensed there was something different about Louis or not. But the audience very well knows that both Louis and Claudia could have very easily stepped in and stopped what was about to happen to them both. Especially since the episode opens up with them slaughtering a large group of German soldiers. Stopping what was happening to Emilia would have been light work.
And I think, in any other show, Louis and Claudia would have stepped in and saved them. To reinforce the idea that they -- she and Louis -- are "good" and "benevolent" vampires, the type Claudia has convinced herself they are and that she is looking for.
And yet? They both turned away very easily from helping two humans who were helpful to them. They, Louis especially, did not play the "magical negro" here. They walked away and did so completely unconflicted about doing so.
Because, in truth, they aren't really benevolent. Not when it comes to humanity. Magical they both are, in the nature that all vampires are. But they are not there to help humans in that "magical negro" trope fashion -- and this goes for all humans, be they white or black or anything else.
Louis now has begun to take to heart that human affairs are not his to get involved with, something he began to learn in the harshest ways possible in Season 1. For better or worse he is part of a different world now. And what that world is and is about is a journey that he will continue to learn throughout season 2.
