Kings Flung Into the Future is a Manga/Manhwa/Manhua in english language, Drama series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The Kings are all here. But “here” is the present day and the “Kings” all happen to be those from the Joseon Dynasty. How did these great rulers from different times in Korea’s past end up here, all gathered in one place? Who could be behind all this? Well, it seems there's a sinister plot being setup by men in dark suits. Men who would like nothing more than to see Korea embroiled in a great war. Bad guys who want to watch Korea go down in flames. There’s only one person who can save the country: a young man named Yi Do, otherwise known as King Sejong the Great. Will the greatest king of them all have the might and wisdom to save the day?