As the master of the School of Unholy Arts and as the undefeated Unmasked Demon, MookHyang unfortunately falls to a strange fantasy world by the magic of his enemies (School of Blood Arts). In the new world of elf, sorcerer, knight, and dragon, MookHyang’s adventure of finding a way back to his old world (Murim) unfolds.

From ilovemanhwa.com:

A HIDDEN WAR AROUND THE SECRET OF SEOUL, THE 600 YEAR OLD CAPITAL OF KOREA. Joo-hee never dreamed he would be investigated in the Presidential Residency by making emergency calls to see the flame from the city center though he felt wrong to know noone else witnessed the flame at school. People from National Fengshui Office said Seoul is in danger, for some people are breaking the seals on the places of bad chi. Indeed, people are killed by unearthly monsters, and not knowing what talent he has, Joo-hee's life is swept to this hidden war.

From: Easy Going Scans

Some corrupted high ranked officers within the palace are accusing the crown prince Sado of high treason and ask for his death! What will the Emperor do to save his son?

A fusion heroic historical about a crown prince in a wooden chest about to meet death, but actually turns out he has bigger influence and authority beyond imagination.

Adapted to K-Drama.