And there it is!
Yamao losing her mind over Momo, left in sheer wonder of him. Confirming that he's the man of destiny that's going to bring the dawn.
BUT THEN!
Momo tells Yamao about how much opening Wano's borders will endanger the country, even though it's the necessary and right thing to do... If only they had some way to help guard Wano once its borders were open...Like some kind of.. guardian of Wano to help...guard Wano...
This is it. It's been obvious in the long run for a while now, but Yamao's post arc plot is finally developing. For the first time, she's been made aware of the reality of the situation and it's just about to dawn on her what she must do.