A martial-arts expert goes after a criminal gang and its boss, who were responsible for the death of his partner.
A group of sadistic mercenaries kidnap people off the streets and set them loose on the grounds of their secret camp, so the "students" at the camp can learn how to track down and kill their prey.
In a future time, when things have reverted back to the days of the Old West, a man goes after the gang that murdered his brother.