Can Defy counter Falling Star's Reflexive Triggers after they've entered the Chain?

Ruling: Defy cannot counter Falling Star's Reflexive Triggers because Defy can only target spells, and the triggers are abilities, not spells. Additionally, Defy cannot counter the Falling Star spell itself due to the 2 power cost restriction.

Nuances:

• Falling Star's own unit does not work with Dreaming Tree because the spell itself isn't targeting the unit—its Reflexive Triggers are, and those triggers are not spells
• Not So Fast would work against one of the triggers (but not the spell itself)
• Wind Wall would work against Falling Star