For the first question, it'd have to be something they train under and strive to work for eventually. You mentioned it would be applicable to those who have strong CR with Kougyoku so that's a good start! So long as it's not an ability they use consistently with expertise from the start, it'll be fine.

As for the other question, that's up to you. They can break the spell if you'd like it broken at any point, but depending on her current involvement with the flight of choice, it might take a bit of planning. For example, if she has a negative standing and works actively against her flight, they might be apprehensive.