When playing Icathian Rain, when are targets selected - at activation or at resolution? Can the opponent react before targets are chosen?

Ruling: Targets are selected at activation when you play Icathian Rain, not at resolution. The opponent reacts after targets have already been chosen.

Sequence:

• Step 1: Play Icathian Rain and pay its cost
• Step 2: Select all 6 targets at activation
• Step 3: Opponent has opportunity to react
• Step 4: Card resolves with the previously selected targets

Nuances:

• If you target a unit with Deflect 1 six times, you must pay 6 additional Power at activation
• If a hidden unit is revealed in response after targets are selected, that unit cannot be affected because targets cannot be changed after selection
• The "Do this 6 times" wording is a shortcut for selecting 6 instances of damage allocation, all chosen at activation