I assume it's health goes to 0 and it is un-assigned from the city.I have a question. Suppose a city which has a hero assigned gets conquered. Then what will happen to the hero?
That's actually a great ideaI'm enthousiastic about the new heroes feature
However, i also think that they shouldn't be implemented on ALL worlds. They should be put only on the most recent ones (starting in 2014), and after that, handle like morale, some new worlds will have "heroes : active" and others "heroes : inactive"