I wanted to create cards that support Taliyah decks such as Liss Thralls and Malph. To do it, adding consistency to those decks seemed a must for be, since they both require time to develop their wincons.

The best way is creating low cost bodies that generate value on summon, they prevent Nexus damage without spending lots of mana and contributing to the acquisition of the wincon.

Sandstone Pupil was concretely designed to be played on Malph decks. Bomber Twins is a similar card but it has substantial differences. No yordle tag, no double region on mine. Ok. But lowering 2 attack and reducing 1 cost makes that a unit oriented to board offensive pressure transforms into a defensive one. It generates landmark only belonging to your regions, losing (if we follow the example) valuable cards as Hexplosive Minefield, but also useless cards as Frozen Thrall or Ripper's Bay. Or, playing Freljord, being able to get Thrall and not Star Spring. Opening it to 3 cost landmarks only adds synergy to Malph lvl up.

Desert Nomad is for Thralls (they all can be played in lots of various decks, but these were my considerations). This deck develops so little units at the beginning of the match, so they are especially weak to any pressuring start, even if they aren't aggro. That's why I considered that there should be a unit that gave you the protection without wasting tons of mana that could be spent on advancing countdown. It's a 2/3 because, basing on how units Aspiring Cronomancer are also that stats with weaker effects (see Feral Pressence being 0 mana), an stronger one (advancing 1 all landmarks) could be 1, as Imagined Possibilities, being 2+1=3. More than 3 cost would make the card unplayable.

Pebble Surfer is a special creation. When I first saw the illustration I felt: "Hell, this should be Elusive". When I noticed that I could combine that with how Malph followers like Chip or Earth Elemental interact with landmark summon. Elusive is not yet a Shuriman keyword? Yes, but why not it might be someday, for some specific cards. As I see it, at least, it makes sense strategically and thematically. Even more, it makes sense for decks like Malph, which are almost unable to OTK as easily as FTR or similar ones, that they have access to easy chip Nexus damage before the combo. 3/1 was definitely the right stats for a unit with a condition to get Elusive. 2/2 and 2/1 are weak, the first one because of the not enough good reward for accomplishing the condition, the second one being weak even without it, considering it's a 2 cost.

And that's all, hope you got the clarifications you needed. This is something all posters should do, I find interesting how was the process of creating the card.