The two witnesses are who? Elijah is clearly shown to be one of them, but who is the other? Let us have a look at the prime candidates. The first is Enoch, and that is because Enoch also did not die. Gen 5/24 Enoch walked with God, but he was not found, for God took him. That does not mean he did not die; it just means he was not found. He did walk with God. That is the only connection, and he is not a character of any significance in the rest of the Bible. One of them is Moses. Moses was with Elijah at the transfiguration of Jesus. Jude says that there was significance in Moses body as Satan was contesting over it.
Satan has nothing to do with Sheol, so why was he interested in it? The other is John the Baptist. Jesus himself said, “For all the prophets and the law prophesied until John. And if you are willing to accept it, he is Elijah”. If John is one of them, is he the second witness, or is it not Elijah but the ministry of Elijah in the person of John the Baptist? My personal guests are Elijah and Moses, for they were on the mountain at the transfiguration of Jesus.

How will they operate in today's world? Will they be two old blokes wandering around performing miracles? If so, how will they get to be so famous that the world will stop and celebrate at their deaths? Modern media would make that impossible. They have to be people of fame who are generally despised. It does not even have to be a leader in Israel. Ester was a Queen of Persia and Moses was a Prince of Egypt. As political leaders, they will have been around in some position will before the 42 months. Benjamin Nytnahu would be a likely candidate. Turkeys Erdoğan looks good as well. Donald Trump could be a Moses. In the USA, he is setting his people free.