What describes the character of Simon Bass in The Shakespeare Stealer?

In The Shakespeare Stealer, Simon Bass is often described as having an "unpredictable" and "dangerous" nature. As the story progresses, he becomes increasingly unhinged and violent, with his actions becoming more extreme and erratic. He is also portrayed as being incredibly secretive, with a hidden agenda that he is reluctant to reveal. Additionally, he is known to be quite manipulative, using his charisma and intelligence to gain the upper hand in any situation.