When an opponent's unit with assault moves into an open battlefield (creating a non-combat showdown), and then I play Ride the Wind to move my assault unit into that same battlefield, which unit is the attacker and which is the defender?

Ruling: The opponent who originally applied contested to the battlefield is the attacker, even after you move your unit in with Ride the Wind.

Sequence:

• Opponent's assault unit moves to open battlefield, creating a non-combat showdown (assault doesn't trigger)
• You play Ride the Wind to move your assault unit to the same battlefield
• Players conclude the current non-combat showdown first
• Combat begins with the opponent still as the attacking player (since they applied contested)

Nuances:

• Assault is a passive ability, not a trigger
• Technically, the combat is marked as staged during the first showdown, but it plays out as described