New Revised Standard Version
When they have finished their testimony, the beast that comes up from the bottomless pit will make war on them and conquer them and kill them,

Contemporary English Version
After the two witnesses have finished preaching God's message, the beast that lives in the deep pit will come up and fight against them. It will win the battle and kill them.

New American Bible
When they have finished their testimony, the beast that comes up from the abyss will wage war against them and conquer them and kill them.

Douay-Rheims Bible
And when they shall have finished their testimony, the beast that ascendeth out of the abyss shall make war against them and shall overcome them and kill them.

And when they shall have finished their testimony, the beast that ascendeth out of the abyss shall make war against them and shall overcome them and kill them.

when.

Revelation 11:3 And I will give unto my two witnesses: and they shall prophesy, a thousand two hundred sixty days, clothed in sackcloth.

Luke 13:32 And he said to them: Go and tell that fox: Behold, I cast out devils and do cures, to-day and to-morrow, and the third day I am consummated.

John 17:4 I have glorified thee on the earth; I have finished the work which thou gavest me to do.

John 19:30 Jesus therefore, when he had taken the vinegar, said: It is consummated. And bowing his head, he gave up the ghost.

Acts 20:24 But I fear none of these things, neither do I count my life more precious than myself, so that I may consummate my course and the ministry of the word which I received from the Lord Jesus, to testify the gospel of the grace of God.

2 Timothy 4:7 I have fought a good fight: I have finished my course: I have kept the faith.

the beast.

Revelation 13:1,7,11 And I saw a beast coming up out the sea, having seven heads and ten horns: and upon his horns, ten diadems: and upon his heads, names of blasphemy. . . .

Revelation 17:6-8 And I saw the woman drunk with the blood of the saints and with the blood of the martyrs of Jesus. And I wondered, when I had seen her, with great admiration. . . .

Revelation 19:19,20 And I saw the beast and the kings of the earth and their armies, gathered together to make war with him that sat upon the horse and with his army. . . .

Daniel 7:21,22,25 I beheld, and lo, that horn made war against the saints, and prevailed over them, . . .

Daniel 8:23,24 And after their reign, when iniquities shall be grown up, there shall arise a king of a shameless face, and understanding dark sentences. . . .

Zechariah 14:2 And I will gather all nations to Jerusalem to battle, and the city shall be taken, and the houses shall be rifled, and the women shall be defiled: and half of the city shall go forth into captivity, and the rest of the people shall not be taken away out of the city.

*etc:

2 Thessalonians 2:8,9 And then that wicked one shall be revealed: whom the Lord Jesus shall kill with the spirit of his mouth and shall destroy with the brightness of his coming: him . . .

out.

Revelation 9:2 And he opened the bottomless pit: and the smoke of the pit arose, as the smoke of a great furnace. And the sun and the air were darkened with the smoke of the pit.