When casting Icathian Rain to deal 8 damage (4 triggers × 2 damage) on a unit with deflect, do you have to pay the deflect cost 4 times?

Ruling: Yes, you must pay the deflect cost for each reflexive trigger that targets a unit with deflect. You can choose not to pay the deflect cost for any or all triggers, even if there are no other legal targets.

Sequence:

• Cast Icathian Rain
• Players can respond
• Icathian Rain resolves, creating 6 reflexive triggers
• Choose targets for all 6 triggers (can target the same unit multiple times)
• Pay deflect costs for each trigger targeting a unit with deflect (or choose not to pay)
• Players can respond
• Each trigger resolves one at a time, with opportunity to respond between each resolution

Nuances:

• You decide whether to pay deflect costs when triggers finalize on the chain, not at resolution - you cannot change your mind later if opponent boosts the target
• Units can die between reflexive trigger resolutions
• You can target the same unit multiple times, even if it has less might than the total damage
• If a unit moves within board zones (battlefield, base, facedown zone, legends zone), it remains a legal target for remaining triggers
• If a unit moves to non-board zones (hand, trash, banishment, champion zone), it is no longer a legal target