There are 2 slots for the rare cards in every pack, they can either be: 2 rare cards 1 rare and 1 super rare 2 super rares 1 super rare and 1 legendary The enchanted cards are actually replacing the reverse-holo card in each pack, so the best value opening of Lorcana the first chapter can be: 1 super rare, 1 legendary and 1 enchanted card
For small amounts of milling, its more efficient than Bruvac the Grandiloquent, and its excellent with some Persistent Petitioners
The 12-mana Emrakul is 12/12 and you steal all dorks a foe controls - note there is no give them back here
Based on this experimenation, it seems like the Sapphire/Steel deck is more aggressive , with new cards boosting Strength and increasing Resistance, while the Amber/Amethyst deck is more about mitigating and removing damage
This protection helps them stay on the board long enough to turn your small group of tokens into a large army