How does Icathian Rain/Falling Star work in terms of targeting, resolution order, and when opponents can react?

Ruling: You play the spell, opponents can react to the spell itself (e.g., with Wind Wall to counter it). If the spell resolves, it creates reflexive triggers - you choose all targets for these triggers, then they resolve in reverse order (last chosen resolves first) with priority pauses before each trigger resolves.

Sequence:

• Play Falling Star
• Players can react (Wind Wall can counter the spell here)
• Falling Star resolves, creating 2 reflexive triggers
• Choose target for reflexive trigger #1
• Choose target for reflexive trigger #2
• Players can react
• Reflexive trigger #2 resolves (dealing 3 damage)
• Players can react
• Reflexive trigger #1 resolves (dealing 3 damage)

Nuances:

• Wind Wall can only counter the spell itself, not the individual reflexive triggers
• If Wind Wall counters the spell, no reflexive triggers are created and no targets are chosen
• Deflect can be applied when choosing targets for reflexive triggers (triggers fail to finalize unless deflect cost is paid)