Builds in different countries

To my knowledge, every country has the same version of the game, so any build that is viable there would be viable here. I think the reason you see things like the "Korean Lucian Build" simply comes from the fact that a pro team sanctioned by that country is among the first to have been seen to utilize that build in a pro-game with a surprising amount of sucess. The closest thing there may be to there being metas in some countries that are ineffective in others, may be a result of some countries being generally better at theory crafting than others. Unfortunately, NA, is not really very good at theory crafting in general, so we tend to be behind the curve, and discover our meta from other countries.