#4 Ivan the Terrible
Ivan IV Vasilyevich, the Grand Duke of Muscovy (Moscow), was the first Russian Tsar (Emperor), the title he gave himself in 1547. It is stated that he suffered from some kind of mental illness because he was extremely intelligent and a great leader but had episodes of outbreak. During these outbreaks, he would enjoy burning thousands of people in big frying pans, as well as impaling them. He earned the nickname Terrible for building a wall around city perimeters to prevent people from escaping. Ivan would sometimes capture 500 people and watch them getting tortured in front of him and his son. He was paranoid and killed many nobles for thinking they want to overthrow him. Ivan the Terrible died from a stroke during a game of chess.