"Ruler" is God, "Master," "Almighty," "Ruler" of the whole universe, because His Laws rule, dominate, govern the whole material and spiritual world.

"Ruler" is Jehovah God, Who by His Wisdom of His Beneficent Will, His Laws, His Commandments, exercises authority, the spiritual guidance of the life of the nations.

"Ruler" is also a symbol of Jesus Christ, who by the undeniable Truth of His Teachings rules, ruling in the minds and lives of those who accept His Teachings.  

"Ruler" is also a symbol of a man who rules over the sinful demands of the flesh, rules his emotions, submitting them to the fulfillment of God's Will, His Commandments.

Negative Meaning     

"Overlord" is a symbol of the cruel political and deceitful religious rulers of the world, its leaders, who in various ways, introducing their destructive ideologies, dogmas, rule, rule over the consciousness and way of life of nations.