Still, I don't want to call it prejudice.
The concept of this card is more than that. These's people don't just have an attitude of hostility, their actively shunning the mutants, and blaming them for all of the problems caused by the grim. All of this will be explained when I release the next entropy card and get to make the actual series thread.
The point is, one side isn't just prejudice against the other. They're actively trying to murder each other. And while prejudice has a denotation that fits the card description, I've always thought it had a connotation of just being an attitude. Nothing more.
I am prejudice against fat people when I assume they are lazy. I am discriminatory towards fat people when I don't feed them.
I am prejudice against people from the fiction land of candy land when I assume they are delicious. I am racist towards them when I call them "sugar-tits" and burn their houses down.
Maybe it's a small difference, but it's enough that I don't think that the term prejudice applies here. While I'm happy to come up with a different card name than "racism", it probably won't be "prejudice".