The Bible does 'Har-Meggidon' means 'a mountain of people gathered together' (Joel 3:2, Zechariah 12:3, Isaiah 29:7, Revelation 20:9, Isaiah 13:4, Ezekiel 32:18, Ezekiel 39:11, Zephaniah 2:1-2, Micah 4:11, etc).

These state all nations come against Jerusalem, and then the Source removes all the ungodly in one day...

Rabbinic Jews think they're Israel, and many of them are part of the problem with 'Jerusalem' being a 'Place of Peace' in the world - thus they also get removed in a day for denying the Bible.

If we analyse the timeline (Revelation 16:16-21, Zechariah 14:1-15, Joel 3:11-15, Isaiah 13:4-10): Armageddon is as the nations come against Jerusalem, and then the stars fall from the sky at the same time it takes place.