lord of nightmares

金色の魔王 (ロード・オブ・ナイトメア)

The ultimate being who created the Slayers universe and at least three other worlds, of which Lost Universe's setting is one of them. He/She is too great to be comprehended, and he/she is simply called the Golden King of the Sea of Chaos. His/Her power is so immense that only Lina Inverse is capable of wielding such power, and even then it's unstable.