This is just the result of various collections of information, you don't have to do it to get a competitive deck. Read the descriptions of the cards before creating them, to see if they can match the decks you want to have.
These 4 cards are decisive in the Highlander Mage, very powerful at the moment in the meta. Discovering a dragon while handling an opposing minion for the Arcane Breath, Reducing the cost of a spell with the Dragoncaster to 0, what more could you ask for a Highlander deck? Oh, yes! Malygos, Aspect of Magic that discovers an improved mage spell. These three cards have only one drawback: they require you to have a Dragon in your hand when you cast them. But between Malygos, the two Alexstrasza and several other dragons, you'll have plenty to do!
On the other hand, the Azure Explorer, which is a little less present than the other three, has the good taste of being a Dragon and discovering a Dragon, in addition to the nice +2 in Spell Damage.
The new Hearthstone extension, Descent of Dragons, is available since December 10. Here is our selection of decks made by professional players or streamers, to have fun once your boosters are open.