Read Revelation 9:11 Using Other Translations
And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
They have as king over them the angel of the bottomless pit. His name in Hebrew is Abaddon, and in Greek he is called Apollyon.
Their king is the angel from the bottomless pit; his name in Hebrew is and in Greek, —the Destroyer.