In both shows you basically have to trust each other to win. Of course there are people who just like to see the world burn and are only looking out for themselves. We have the hero protecting the damsel but can we really trust him? Engaging and intriguing- you will be glued until the last second.
In I saw the Devil a man is getting revenge from the serial killer who killed his wife and unborn child. In The Five a lady gets revenge from the serial killer who killed her family. Very similar plot but with different ways of getting the bad guy.