In a Showdown, when there are Attack and/or Defend triggers on the initial chain, which player gets priority first to play a reaction?

Ruling: The player who owns the last item on the chain has priority first. In both scenarios (Attack and Defend triggers, or only Defend triggers), this is the defending player.

Nuances:

• Focus is the permission to start a chain during a showdown and passes automatically when chains empty
• Priority is the permission to play something to a new or existing chain and passes back and forth frequently as players build and resolve the chain