In my first attempt, there was 2 questions:
-What is "that province" on Hakahime: Zen answered that.
-What if I use Hakahime to use Wait and see in the current battle (reason why I use "when defending" in the title): Zen missed that one (He's a human, that's normal).
So I will make it even more precise:
-I'm playing Shiro Kitsuki.
-I have Hakahime attached to one of my province.
-My opponent attacks me where Hakahime is attached.
-Shiro Kitsuki is unbowed.
-It is battle action segment.
-We are at the battle on the province where Hakahime is attached.
-I put Hakahime which was attached to the province currently under attack
in play, then use her reaction to play Wait and See, and then destroy the province we are fighting at.
=What happens to the battle action segment?