Fomo for a week. Bitcoin price would crash like 25%. After that all the miners from south korea will move their mining farms to a country around and start on a other place their mining and the price of bitcoin would rise again and maybe the network is more overloaded after that.
And what's happened in China?
Chinese miners are moving to Canada and Europe and are being welcomed with open arms. China will lose money on this but it's their choice. They won't take the offer so somebody else will.
There won't be an overload caused by a ban in Korea, even if they eventually ban it in a year or 2. Koreans aren't running a mining powerhouse as opposed to the Chinese and if China hasn't banned mining yet I doubt that Korea will. The effect of a ban would be Korea losing money on it, Koreans moving exchanges and money abroad, miners moving their farms, that's it.