If defending Kayn retreats using Reavers and then uses Ride the Wind to return to the battlefield during the same combat, does the Kayn player score from this combat?

Ruling: Yes, the Kayn player scores from this combat. Kayn remains the defender throughout the showdown because attacker/defender roles are determined at the beginning of the showdown and don't change until it resolves. If the attacking player cannot kill Kayn through non-damage sources, their units will retreat and the Kayn player scores for conquering. The Kayn player can also score again at the beginning of their next turn for holding the battlefield.

Sequence:

• Defending Kayn retreats using Reavers during combat
• Kayn uses Ride the Wind to return to the battlefield
• Kayn remains the defender since this all occurs in the same showdown
• Kayn no longer takes damage from the combat after moving out and back in
• If attackers cannot kill Kayn through non-damage sources (like Hidden Blade or movement effects), attacking units retreat
• Kayn player scores for conquering as the defender
• Kayn player can score again for holding at the start of their next turn

Nuances:

• Riot devs have confirmed that defenders can conquer, though some rule text may seem contradictory and will be clarified in future rule updates
• The attacking player would need non-damage kill effects or movement abilities to prevent Kayn from winning, since Kayn doesn't take damage after the Reavers/Ride the Wind sequence