The main theme of game of thrones is that doing good will get you killed. Good guys die. That's just the way the world works. It's a true and proper reflection of the bitter truth of this world. The bad people always win because they play dirty and the good guys keep losing because they don't do what needs to be done to win.

But at the same time the series also shows that being bad isn't always perfect because karma catches up with everyone. And as such, every antagonist in the series eventually dies a gruesome death that matches the cruel way they have lived their lives. This is seen in Geoffrey's choking to death, little finger, the silent killer getting his throat slit open and Ramsey Bolton, the brutal murderer getting eaten by dogs.

These themes and the show help to represent the real world and the way it works in a way that no other series of movie does. Can't wait for the next season to come out