These four puzzles, Sapphire, Emerald, Amber, and Ruby, will be released at all retailers in September and the amethyst and steel puzzles will be exclusively sold at Disney stores in the United States, but in Europe all six puzzles will be sold at all retailers
Amethyst cards are usually magic-focussed, Amber relates to healing and protection, Steel and Ruby cards tend to have higher challenge power, Sapphire is more strategy-focussed, and Emerald is a bit of everything
Aurora, Dreaming Guardian is the ideal combo card, working with the rest of your Sapphire deck to keep that lore going up and your characters safe
Eye of Nidhogg overwrites all previous effects that set the creature's base power and toughness to specific values
With that said they may have a few insignificant flaws that are minor