When Yasuo and Merchant move to attack, what is the correct order of triggers and when can each player activate abilities?

Ruling: Merchant's on-move trigger resolves completely before the showdown begins (you cannot start combat with a chain). During the showdown's initial chain, the defender controls the order of all their triggered abilities, regardless of whether they trigger on attack or defend.

Sequence:

• Yasuo + Merchant move
• Merchant trigger goes on chain and resolves (outside showdown)
• Showdown begins with initial chain
• Attacking player (with Focus) adds their triggers first (Yasuo trigger)
• Defender adds all their triggers and chooses their order (Ahri Legend trigger, Ahri Champion trigger, Battlefield trigger)
• Chain resolves

Nuances:

• The defender chooses the order for all abilities they control that trigger, not just on-defend triggers
• Ahri leader creates separate triggers for each attacking unit (one for Yasuo, one for Merchant), resulting in 4 total defender triggers