For Icathian Rain, do you target units and assign damage before or after the opponent can play actions/reactions?

Ruling: Icathian Rain does not target when initially played. After opponents can react to the spell itself, it resolves and creates 6 reflexive "deal 2 damage" triggers. You then target all 6 triggers at once before opponents can react to those triggers.

Sequence:

• Play Icathian Rain (no targeting yet)
• Opponents can react (e.g., counter the spell)
• Icathian Rain resolves, creating 6 pending "deal 2 damage" triggers
• You target all 6 triggers at once and put them on the chain
• Opponents can react to the triggers
• First trigger resolves (damage dealt)
• Opponents can react
• Second trigger resolves
• Continue until all triggers resolve

Nuances:

• Icathian Rain is an outlier - most spells target when initially played, but IR's "do this X times" formatting creates reflexive triggers that target separately after the spell resolves
• You must declare all targets for all 6 triggers simultaneously before opponents can react to any of them
• If targeting units with deflect, you pay those costs when finalizing the triggers onto the chain