All Cards in the list are free to anyone when you start the game.
The aim of this deck is to control the early game with your Marksman and Brontes minions and then play an aggro late game with Athena, Fury and Brute. You will also have decent draw power because of your Elder Harpy.
On Turn 1, you should always be focused on playing a Marksman, this is because if you can keep him around for the mid game, he should be quite heavily buffed and be a good way to close out the game.
When opening packs, you are likely to come across some extra cards.
You should experiment with the deck with your own cards.