How does Mercutio use language to maintain character consistency even in death?

Mercutio is a tough and dramatic talker even near death. From his witty challenges to Tybalt to his passionate Queen Mab speech, Mercutio is able to make a statement about his feelings as well as the state of society. As Tybalt realizes he is going to die under Romeo's arm, he shouts, A plague o' both your houses! He curses both Capulet and Montague for his own senseless death.