Ishiwara Katsu is a ruler in the Modern Era. He is the military ruler of Higematsu, Igamoto, Igioka, Kibakuguchi, and Kyushima.
He is a general under Emperor Hisao Hito that uses terrorism to control his conquered people. He rounds them up then massacres them, and no one is spared under his rule, not even children. In order to establish control over his provinces, he tortures and murders the local people by the thousands. He even encourages the people to betray each other. Later, in this quest, it is revealed that Ishiwara wanted to overthrow his emperor, but when he gets to the palace, he is assassinated, or if you chose to fight Ishiwara, he is executed. Therefore, like what Princess Myciena von Maidenport said, he was probably well informed about the plot.
He is based off Japanese General Ishiwara Kanji, who was one of the men responsible for the Mukden Incident that gave the Japanese a false pretext to invade Manchuria.