What happens to Kayn when he uses his ability to avoid taking damage during a gank, but loses the showdown because he can't kill all enemy units on the battlefield?

Ruling: Kayn is recalled to base in whatever state he was in when he ganked (exhausted).

Sequence:

• Kayn uses his gank ability and becomes exhausted
• Kayn uses his ability to avoid taking damage during the showdown
• Kayn loses the showdown because he can't kill all enemy units
• Kayn is recalled to base, remaining in his exhausted state