Well, while I am not at liberty to tell you which cards were made to play nicely with Khans of Tarkir block, I can say that it is normal practice for us to make sure that a handful of cards in each core set play nicely not just with the current environment, but the future environment as well
These animalfolk love instants and sorceries, opening up a unique spellslinger style
This octopus wizard works fine in discard and connive decks, but thats a weird counterspell-adjacent ability that I could see myself forgetting about most of the time
Of course you don't
This is the first black creature with the subtype Crab, and while weve had some black oozes printed before, I dont think theres enough cards out just yet to make a crab ooze horror tribal list so I dont think people will run this card for its power is equal to effect too often
This doesnt mean enfranchised players cant enjoy the themes or decks, but Id expect this to be uninteresting to most without significant reprints like the Tempest Medallions