When casting Icathian Rain and choosing the same Deflect unit multiple times, can you decline to pay some of the Deflect costs, and when can opponents react?

Ruling: When Icathian Rain resolves, you choose all 6 targets and decide which Deflect costs to pay simultaneously. You can decline to pay Deflect for any triggered abilities, and only the triggers you paid for enter the chain. Opponents can then react to those triggers before they resolve.

Sequence:

• Cast Icathian Rain
• Window for reactions (if none, it resolves)
• When it resolves, choose all 6 targets at once
• Decide which Deflect costs to pay (you may decline any)
• Only the triggers you paid for enter the chain
• Players gain priority to react to those triggers
• Each trigger resolves individually with reaction windows between them

Nuances:

• This ability to decline Deflect costs only applies to triggered abilities (like Icathian Rain's reflexive triggers), not to casting spells directly
• If there are other legal targets available, you cannot choose to hit nothing - you must select legal targets
• No one can react in the middle of the targeting and paying costs process
• This rule changed in a recent rules update; it did not work this way previously