Hey, yes it should support Korean. This is the list of languages https://www.ubisoft.com/en-gb/help/assassins-creed-valhalla/connectivity-and-performance/article/language-options-in-assassins-creed-valhalla/000079384

If any trouble email [email protected] and we'll help you out. Can refund if you find it's not included. But it should be :)