The Dreadful League of Black Knights consists of former Tournament winners who got so cocky with themselves that they thought they stood above everyone else. They sought out dark magicks to become even stronger but it has corrupted their souls and constantly drains their life force ever since. Now they are only alive by stealing energy from the Realms and usurping their inhabitants.
The Black Knights are the main bosses in the game. Each Realm contains one Knight that holds it in terror. You have to defeat all seven of them and free the Realms to find the Sun stolen from your Kingdom.