So, the second beast is not Satan, as was claimed, since the second beast is the false prophet and the scripture clearly differentiates between the dragon and the false prophet. The dragon represents Satan and the second beast/false prophet represents something else.
Because the first beast is still the 7 headed dragon from chapter 12 and the scarlet colored beast in chapter 17. The entire beast is the world empire system since Babylon and Nebuchadnezzar who had the dream of the image that contained the first 5 heads, or kingdoms.
The FP is the mouth of this beast system after the 7th Trumpet has sounded.
"And there was given unto him a mouth (the FP) speaking great things and blasphemies; and power was given unto him to continue forty and two months."
The beast of the sea is not one single person, nor kingdom. It is the whole historical world government since Daniel.
Satan is the beast from out of the earth, the pit, with the voice of the dragon, Satan's own voice. Satan is the one who kills the 2 Witnesses after the 42 months are over in the above verse. Satan will rule for 42 months as the 8th king and kingdom after Jesus is declared the 7th King of the 7th Kingdom in Revelation 11 when the 7th Trumpet sounds.
"And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever."
Jesus reign is eternal, but put on hold if Satan is allowed 42 months as the 8th kingdom.
"And there are seven kings: five are fallen, and one is, and the other is not yet come; and when he cometh, he must continue a short space. And the beast that was, and is not, even he is the eighth, and is of the seven, and goeth into perdition."
This is still Satan the beast out of the pit.
"And when they shall have finished their testimony, the beast that
ascendeth out of the bottomless pit shall make war against them, and shall overcome them, and kill them."
"And I beheld another beast
coming up out of the earth; and he had two horns like a lamb, and he spake as a dragon."
Satan has all the power of the dragon, sea beast and scarlet colored beast, because he is part of the power these historical world empires relied on. Many claim Satan was already in control of the earth, but never as a king recognized by all humanity. That only happens those last 42 months between the 7th Trumpet and Armageddon. And only if God determines that in the midst of the week of the days of the 7th Trumpet. It is not guaranteed. Only a reality that John saw could happen, not that it has happened already.
Satan offered Jesus the world power while the 4th head was still in power, but it was not time. Jesus will be the 7th Kingdom declared by God, not something given by Satan. Satan will only have Revelation 13 if God allows it. Otherwise the world gets Revelation 14 and the winepress of God's wrath to clear and restore creation for the Day of the Lord.