Can you use Stupefy in response to your own Icathian Rain trigger after an opponent reveals Hidden Zonya's, to force the Zonya's to target a different unit?

Ruling: Yes, this is legal. After the opponent reveals Hidden Zonya's in response to an Icathian Rain trigger, you have priority to respond before Zonya's resolves, allowing you to cast Stupefy to kill another damaged unit and force the now face-up Zonya's to activate on that unit instead.

Sequence:

• Cast and resolve Icathian Rain, adding 6 reflexive triggers to the stack (each dealing 2 damage)
• Target First Mate with trigger 1, Yi with triggers 2-5, and First Mate with trigger 6
• Triggers resolve one at a time: trigger 6 resolves (First Mate has 2 damage), trigger 5 resolves (Yi has 2 damage), trigger 4 resolves (Yi has 4 damage)
• Opponent responds to trigger 3 by revealing Hidden Zonya's (First Mate has 2 damage, Yi has 4 damage)
• Before Zonya's resolves, you can cast Stupefy on First Mate to kill it (2 might with 2 damage)
• The now face-up Zonya's is forced to activate on First Mate
• Remaining triggers resolve and Yi dies

Nuances:

• Each Icathian Rain trigger deals 2 damage and resolves separately, not all at once
• If the opponent waits until the final trigger to reveal Zonya's, Yi would already be dead from the 4th trigger dealing the lethal damage