Addressing the OP... My, My, MY. First on the video, Colossians 2:8 "Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.
second the two witness are John the baptist, and the Lord Jesus the Christ. and their witness are still in the earth today, the Gospel, the good news, and water baptism.
third,
the fire, not literal, suportive scripture, Jeremiah 5:14 "Wherefore thus saith the LORD God of hosts, Because ye speak this word, behold, I will make my words in thy mouth fire, and this people wood, and it shall devour them".
Hosea 6:5 "Therefore have I hewed them by the prophets; I have slain them by the words of my mouth: and thy judgments are as the light that goeth forth".
the fire here is the Word of God, the "TRUTH". this is how, or in what MANNER, they, the false prophets are devoured, and killed.
PICJAG.