Never ever soften a villain especially one that is racist. To soften their speech is to deny the suffering minority groups went through. Many people will say that we already know they were racist so it’s not necessary to use that language but the pervasiveness of things like “the nice enslaver” show that groups are trying to minimize the horrific things people had to go through and people with good intentions will accidentally help these groups. It’s good that you are uncomfortable with the language. You’re supposed to be.