This allows them to put in weird reprints to help curb some of the price increases
Seven of the 15 mythics in the set are worth more than the $10 MSRP of the pack they come from, and the high end is doing just fine with Jace, the Mind Sculptor, Imperial Recruiter, Ensnaring Bridge, and Chalice of the Void, but after the seven good mythics, there's a massive drop off from Animar, Soul of Elements at around $13 to Gisela, Blade of Goldnight at under $4
Rumbling Engine allows the player to draw until they have six cards, but adds the stipulation that players must discard an energy card, making it a bit more balanced
Among the several cards that are presented, the Secret Rare version of Inteleon stands out
Boil, Boiling Seas, and Flashfires are all pretty specifically tailored to combat mono-blue or mono-white builds that are running a sizable number of basic lands
Terra, Magical Adept / Esper Terra Terra, Magical Adept, discounting the transformed side, is already a good 4/2 creature that mills and gives you a little value