When a 'when I defend' trigger exists and the opponent passes focus during an attack, does the defend trigger or an action speed card played from hand resolve first?

Ruling: When a 'when I defend' trigger goes on the stack, you can play cards from hidden at reaction speed, and those hidden cards will resolve before the defense trigger occurs.

Sequence:

• Defend trigger goes on the stack
• You can now play reaction speed cards from hidden
• Hidden cards resolve first
• Then the defense trigger resolves

Nuances:

• Yi Legend specifically is a passive effect that is always on, not a trigger, so it doesn't use the stack unless there are 'when I attack' or 'when I defend' effects involved