I gave Mr. Z's most recent video a watch and to simply put it's awfully biased and quite the character assassination.
-He leaves out the main reason for the Potawatomie Massacre which was the Sacking of Lawrence by pro-slavery militias
-He calls the men who were killed during the massacre "innocent" when in reality the men were involved with Lawrence
-He tries to compare Brown's planned rebellion in the South to a hypothetical rebellion in North California without really giving an explanation of why on the latter
-He claims John Brown was genocidal to any and all white southerners despite Brown sparing a number of southern whites during his campaigns in Kansas
-He says anyone that sympathizes with Brown is a "liberal historian" even though most historians agree John Brown was a loon regardless of their personal politics
My freshmen and sophomore year teacher in high school let us play Age of Empires 2 on Fridays. He'd play with us too using the Persian Elephant Train. Sadly he passed away about 3 years ago.