If an opponent uses Icathian Rain and targets Volibear Furious (who has Deflect) with all instances, does each targeting trigger Deflect separately?

Ruling: Yes, each time an instance of damage targets a unit with Deflect, the opponent must pay the Deflect cost for each targeted instance separately.

Sequence:

• When a spell targets a unit with Deflect multiple times, each instance creates a separate Deflect trigger
• As each trigger enters the chain, the opponent may choose whether to pay the Deflect cost
• If they decline to pay for a trigger, that trigger does nothing
• Once the choice is made for each trigger as it enters the chain, it cannot be changed later

Nuances:

• The opponent can choose to decline paying the Deflect cost for any individual trigger, causing that trigger to do nothing
• This choice is locked in when triggers enter the chain - you cannot change your mind after seeing your opponent's reaction
• Deflect only requires payment from opponents, so if you target your own unit with Deflect, you do not have to pay the cost