When a unit with a 'when defending' retreat ability is at the battlefield and the opponent plays Yasuo (with a 'when attacking' ability), which effect triggers first?

Ruling: When attacking triggers go onto the chain first, followed by when defending triggers, then the chain resolves backwards.

Sequence:

• When attacking triggers (like Yasuo's) go onto the chain first
• When defending triggers (like the retreat ability) go onto the chain second
• Chain resolves backwards (defending trigger resolves first, then attacking trigger)

Nuances:

• This means you can retreat the unit before it takes damage from Yasuo