Nice queens lay nice bees and mean queens lay mean bees. It’s hard to explain the minutia without using field specific terms, but I assure you that’s how it works every time.
By using a queen from my mean bees, I am adding more mean bees to the population of my nice bees. (as the queen lays more mean bees, the ratio of mean bees in the colony will go up steadily as the colony grows.)
Within a year I expect the colony to be completely mean unless I can find a suitable nice colony.