"Doth right", an archaic phrase that means doing what is right or righteous, can have various antonyms depending on the context. One opposite term could be "doth wrong", indicating the opposite action of doing what is right, or acting immorally. Another antonym could be "acts unjustly," pointing to the character's tendency to treat people unfairly.
Other antonyms of "doth right" can include: dishonest, corrupt, unrighteous, unjust, unprincipled, immoral, and unethical. These terms all signify a departure from the moral path that "doth right" represents. Ultimately, what constitutes an antonym for "doth right" depends on the context and the specific moral values at stake.