Balarant
Balarant (バララント) is the emperor of the Sumer Empire. When he heard about the Blue Crystal Rod, he ordered the attack to Babylim and took over the kingdom with his army. Balarant appears in The Blue Crystal Rod.
Gil and Ki may interact with him during their quest. They may discover that he and Sumer Empire were being manipulated by the demon Anshar.
In The Nightmare of Druaga: Fushigino Dungeon, the description of the item "Black Knight's Shield" says that Balarant sold his soul to the devil.