In a Riftbound showdown, when a vanilla unit (no abilities) contests Reaver's Row and only the defender has a triggered ability from Reaver's Row, who has priority after the initial chain is created?

Ruling: The attacking player (contester) has priority after the initial chain is created, even if they did not add any triggers to the chain.

Sequence:

• Attacker contests the battlefield and gains focus and priority
• Showdown begins and triggered abilities are finalized on the initial chain (defender's Reaver's Row trigger is added)
• Finalization does not pass priority
• Attacker retains priority and can play the first action card

Nuances:

• The attacker gains focus when the showdown begins, which also grants them priority
• The finalization process (adding triggered abilities to the initial chain) explicitly does not pass priority
• This ruling applies regardless of whether the attacker has their own triggered abilities or not
• The rule that "the player who creates the chain becomes the first active player" does not override the showdown-specific rules about focus and priority