All Cards in the list are free to anyone when you start the game. The site says that Sacred Warrior isn’t but you should have the card when you make the deck. (It is free).
The aim of this deck is to survive the early game by clearing the board and making good trades. Once both players get to around 7 mana, you should have the upper hand because of the amount of big minions you have (this will overwhelm the player and net you the win).
You should always be searching for Sobek because it is strong early, and if you can keep it on the board until late game, it will be a monster. Sacred Warrior will allow for early card draw also.
When opening packs, you are likely to come across some extra cards.
You should experiment with the deck with your own cards, the most important ones for this kind of deck would be:
Commons – Khepri, Serqet, Magma Slam,
Rares – Baboon, Oogway, Dune Guardian, Bastet, Chieftain, Focused Blast, Gladiator
Epics – Blademaster, Kang, Bull Demon King, Scarabs Blessing, Thoth, Anhur
Legendaries – Annihilation, Fire Giant, Isis, Anubis, Book of the Dead, Mercenary