When units move to a battlefield with Ahri (who debuffs attacking units), can the attacker play Giant Strength after the defender passes priority on the defend triggers but before combat resolves?

Ruling: Yes, the attacker can play Giant Strength after defend triggers resolve but before combat. When units move to the battlefield, attack/defend triggers (including Ahri's debuff) go on the chain first, then the attacker gets focus to play actions before combat resolves.

Sequence:

• Move units to battlefield
• Attack/defend triggers of the turn player (attacker)
• Attack/defend triggers of the next turn player (defender, including Ahri's debuff)
• Focus to attacker (can play Giant Strength here)
• Pass priority to defender
• Resolve combat

Nuances:

• Ahri's debuff is fixed at the time her trigger resolves in the initial chain, so if tokens are 1/1 when her trigger resolves, the debuff is calculated as 0 for that combat
• After Ahri's trigger resolves, the attacker can still buff their units with actions like Giant Strength before combat actually resolves
• Simply asking if the defender wants to move units back from the battlefield is not passing your action - it's just passing priority on chain triggers