Can you play Arise (Azir signature spell) without Sand Soldiers on board, and does the ready effect only apply to Sand Soldiers played by Arise?

Ruling: You can always play Arise regardless of how many Sand Soldiers or equipment you have on board. Arise does not target and only cares about the number of equipment you control to determine how many Sand Soldiers to play.

Sequence:

• Check number of equipment you control
• Play that many Sand Soldiers
• Ready up to two of them (intended to be the ones just played)

Nuances:

• The "ready two of them" effect is intended to only ready Sand Soldiers played by Arise, but as currently written the rules don't technically support this because units aren't played until after the spell resolves, so the ready effect can't affect them
• The card will likely receive errata to fix this timing issue, possibly using a delayed passive trigger to cause the first two Sand Soldiers to enter ready