Romeo fights Tybalt in the street because of his pride.
Moment of Critical Discovery
Juliet has died!
Romeo also shows pride when he attacks Tybalt after Tybalt kills Mercutio.
Fate Worse Than He Deserves
I think Romeos Reversal of fortune was when he killed Tybalt. This action sealed his fate because if the prince was feeling gracious, which he was, Romeo would be banished. If he wasn't then he would be killed.
Pity for Tragic Hero
Romeos critical discovery is when Balthazar tells Romeo about Juliet's death.
Romeo's so heartbroken he kills himself.
The two houses come together because of their childrens death.