Revelation 19:21

Then the rest of them [i.e., the kings and their armies. Verse 19] were killed with the sword that came out of the mouth of the One riding the horse. And all the birds gorged on their flesh.

Revelation 1:16

And He had seven stars in His right hand [See verse 20], and a sharp, double-edged sword came out of His mouth. And His face [shone] as the sun, shining in [all] its brilliance.

Revelation 17:16

And the ten horns and the beast you saw will hate the prostitute and will take away everything from her, leaving her naked; they will eat her flesh and will burn her up with fire.

Revelation 19:11-15

Then I saw heaven open, and there before me was a white horse whose rider was called "Faithful and True." And He [i.e., Christ] judges and wages war in a just way.

Revelation 19:17-19

Then I saw an angel standing in the sun, and he called out in a loud voice to all the birds that fly in midair, "Come and be assembled together for the great supper of God,

Treasury of Scripture Knowledge

Summary

And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth: and all the fowls were filled with their flesh.

Bible References

The remnant

Revelation 19:11
Then I saw heaven open, and there before me was a white horse whose rider was called "Faithful and True." And He [i.e., Christ] judges and wages war in a just way.
Revelation 1:16
And He had seven stars in His right hand [See verse 20], and a sharp, double-edged sword came out of His mouth. And His face [shone] as the sun, shining in [all] its brilliance.

And all

Revelation 19:17
Then I saw an angel standing in the sun, and he called out in a loud voice to all the birds that fly in midair, "Come and be assembled together for the great supper of God,
Revelation 17:16
And the ten horns and the beast you saw will hate the prostitute and will take away everything from her, leaving her naked; they will eat her flesh and will burn her up with fire.