If you're defending, can you use Arcane Shift to banish and replay Blue Ahri from/onto the same battlefield to trigger her 'When I Defend' ability a second time in the same combat?

Ruling: Yes, you can trigger the 'When I Defend' ability a second time. When a unit is banished and replayed, it becomes a new game object that never saw the first trigger happen, so it can trigger again even in the same combat.

Nuances:

• While units normally only trigger their 'When I attack/defend' abilities the first time they gain the attacker/defender designation in a combat, banishing creates a new game object that is treated as never having triggered before
• This interaction is a core combo for cards like Watcher when defending