I'm presently working on a document about the timing of the antichrist and the false prophet.
I just finished Revelation chapter 13.
It is interesting to note that the antichrist is not mentioned from Revelation chapter 6 to Revelation chapter 13.
The antichrist is also not mentioned from the 2nd seal to the 7th Trumpet, in the book of Revelation.
This is because the seals and the trumpets are chronological, and Jesus wanted them together, and except for the 7th Trumpet they come before the antichrist rules.

So, in the first half of the tribulation, for 3.5 years, you have the 7 seals and the first 6 trumpets.
Then, in the last half of the tribulation, for 3.5 years, you have the time of the antichrist ruling the world.

Then, the 7th Trumpet and the Rapture.
Then, the 7 vials of God's wrath are poured out.
Then, Jesus returns at His 2nd Coming.
Then, the battle of Armageddon.
Then, Jesus rules with His Saints on Earth for 1,000 years.