revelation

Abaddon (Hebrew)/Apollyon (Greek)

And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit. [Rev. 9:1 KJV]

How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! [KJV Isaiah 14:12]

“How you are fallen from heaven, O Day Star, son of Dawn! How you are cut down to the ground, you who laid the nations low! [Isa 14:12 RSV]