Revelation 9:1-2
And the fifth angel sounded; and I saw a Star fall from the heaven to the earth; and there was given to him the key of the bottomless pit.
Revelation 9:11
For they had a king over them, the angel of the bottomless pit, whose name, in the Hebrew language, is Abaddon; and in the Greek, he has the name Apollyon.
Revelation 11:7
And when they shall have finished their testimony, the savage beast which ascends out of the abyss, shall make war against them, and shall conquer them, and kill them.
Revelation 17:8
The beast which you saw, was, and is not; and he will ascend out of the bottomless pit, and go to destruction; and the inhabitants of the earth (whose names are not written in the book of life, from the foundation of the world) shall wonder, seeing the beast who was, and is not, yet shall be.
Revelation 19:20
And the beast was taken captive, and with him the false prophet, who had wrought signs before him, by which he deceived those who received the mark of the beast, and those who worshiped his image; both of whom were cast alive into the lake of fire which burned with brimstone.
Revelation 20:1-3
And I saw an angel descending from heaven, who had the key of the abyss, and a great chain in his hand.
Revelation 20:14-15
And death and hades were cast into the lake of fire: this is the second death.