How does Moon Shadow's father change in Chapter 5 of "Dragonwings"?

Moon Shadow's father is angered by the fact that Black Dog sought retribution against his son. For years, Windrider has stayed away from gang life, but Black Dog's attack on his son, as well as the theft of the money Moon Shadow carried causes Windrider to vow to kill Black Dog. By the end of the chapter, he has killed several gang members.