Yeonliji - Manga
Summary
The world which was ruled by those called the descendents of god and had unique abilities: Heuk's (Black) clan and Sahwa's clans.
One day, Heuk's clan was destroyed by one of the average human clans, the Parang (Blue) clan. The Sahwa clan sends their heir, Gayeon, as bride to the Parang clan's heir as a sign of obedience.
But the one who's actually sent is the the heir's twin brother, Jayeon. Now, Jayeon lives amongst the Parang clan....