Final answer:
The chief forester described as a 'treacherous villain' would be characterized as 'deceitful,' which suggests a betrayal of trust.
Step-by-step explanation:
The personality traits of the chief forester that can be inferred from the sentence "The chief forester was a treacherous villain!" would be deceitful. The use of the word treacherous implies a betrayal of trust and an intent to deceive, which eliminates the possibilities of the chief forester being honest or loyal. Therefore, among the given options, the most fitting word to describe the chief forester's personality trait is deceitful.