'King' in the Bible

They have over them as king the angel of the abyss: his name in Hebrew is Abaddon, and in the Greek tongue he hath the name Apollyon.

And they sing the song of Moses the servant of God, and the song of the Lamb, saying, Great and marvellous are thy works, O Lord God, the Almighty; righteous and true are thy ways, thou King of the ages.

These shall war against the Lamb, and the Lamb shall overcome them, for he is Lord of lords, and King of kings; and they also shall overcome that are with him, called and chosen and faithful.