What tybalt did was battery and equal force would be anything up to a punch to the face or even to the gut and THEN choosing to walk away right after would be excellent legal defense against verbal assault AND battery committed by Tybalt. Had Tybalt just told the MC to leave, he would have been in the right. Instead, he chose to do the other two things first. A person who is attacked or believes that they are about to be attacked may use such force as is both necessary and reasonable in order to defend himself/herself. If that is what is done then the person has acted lawfully. It follows that a person who starts the violence, the aggressor, cannot rely upon self-defence to render their actions lawful.
Your explanation isn't an explanation, it's just an attempt to insult, troll and be argumentative.