When a reflexive trigger targets a unit with Deflect, can you choose not to pay the Deflect cost, and what happens to the ability?

Ruling: When a reflexive trigger targets a unit with Deflect, you can choose whether to pay the Deflect cost. If you choose not to pay, the ability does not finalize and is removed from the chain.

Sequence:

• Reflexive triggers are created as pending items
• When choosing targets for each pending trigger, if you target a unit with Deflect, you must decide whether to pay the cost
• If you refuse to pay the Deflect cost, that trigger does not finalize and is removed from the chain
• All pending items must finalize (or be removed) before players can add reactions

Nuances:

• This is different from regular spells/abilities played from hand - those require you to pay Deflect cost when initially played if targeting a Deflect unit
• The ability that doesn't finalize never reaches the chain fully, so it doesn't count for effects that care about finalized spells/abilities
• If a unit gains Deflect after being chosen as a target but before the trigger finalizes, you don't need to pay Deflect for that already-chosen target
• Players cannot react between individual reflexive triggers finalizing - all pending items must be placed on the chain before reactions can be added