needlessly complex. Just make the castle upgrade the cost of your 'returning' the land set and voila... unlock the extra level.
How bout no, first off, there has been no effort put into this, all you did is throw a wall of text at us and expect us to understand everything, also this would be an awful idea, the only useful land set to do this on would be the lowlands, all the other lands cost way too much as well as their buildings
There are these things called periods, although I'm guessing periods are the reason you aren't using them grammar wise... Anyway! I support!
Holy crap. That is one hell of a sentence ... I counted 1 period in the first two paragraphs. I think it may even have been an accident.