Medieval knights and soldiers wielding huge steampunk guns, while still using swords and armor
If you are playing Cryptic Command you need more blue sources and as such you will have more blue mana early and so you will want things to spend it on
As for why the six-month separation is now being broken, with Amonkhet being pushed back to where the Spring set used to be well get to that as well
And the fact that they tend to follow where dragons go means itd be super easy to create a really fun synergy between the two tribes
Book 1, Book 2, and Book 3 scene cards appear in non-foil and traditional foil in Play Boosters and Collector Boosters
If such things interest you, might I recommend starting here, here, here, here, and here?