Joker;
The Joker acts as the primary antagonist in 'Batman: The Killing Joke'. At the beginning of the novel he is a retired engineer who attempts to become a comedian. However, his newfound career fails and he helps navigate criminals through a chemical plant so they can commit a robbery. Yet, the joker is not inherently evil as he has the intention to support his pregnant wife through the money he is offered. This is also shown as he attempts to withdraw from the scheme. Subsequently, due to the death of his wife and unborn child as well as the immersion into chemicals he becomes completely insane. This is demonstrated through his bouts of violence and murder of the Gordon family as well as his attempts to taunt Batman. The comic concludes with the Joker somewhat reconciling with Batman displaying potential for him to evolve.
Batman;
Batman acts as the protagonist and hero of the comic. He is shown to be heroic and virtuous as he attempts to stop the robbery and disturbance that occurs at the chemical company. This is also shown through his attempt to capture the Joker after he murders and harms the Gordon family. Moreover, Batman is shown to be kind and understanding as after capturing Joker he offers him help to recover.
Commissioner Gordon;
In the comic, Commissioner Gordon is shown to be brave and strong as he is able to endure a beating from Joker as well as psychological torture. His ability to maintain his morals and sanity afterwards by insisting Batman is captured by the book shows that he is virtuous and an upstanding citizen.
Barbara Gordon;
Barbara Gordon is a very minor character in the comic. She is shown to be a victim of Gordon who is forced to endure a bullet to the spine as well as other wounds. Although no detail is provided regarding this, it can be extrapolated that her survival demonstrates her inherent strength.
