They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon and in Greek is Apollyon (that is, Destroyer). Apocalypse 9:11 (NIV) ✝
"What is dark clings to what is light and so enhances the brightness of the latter. A luminous thing giving out light must have within itself something that perseveres; otherwise it will in time burn itself out. Everything that gives light is dependent on something to which it clings, in order that it may continue to shine." - The I Ching: Li / The Clinging, Fire (30).