Obstinate : stubbornly refusing to change one's opinion or chosen course of action, despite attempts to persuade one to do so. Cunning : having or showing skill in achieving one's ends by deceit or evasion. Prudent : acting with or showing care and thought for the future. Trustworthy : able to be relied on as honest or truthful. Discreet : careful and prudent in one's speech or actions, especially in order to keep something confidential or to avoid embarrassment.