The beast that ascends out of the bottomless pit is first mentioned in Revelation 11:7 when he kills the two witnesses after their 3½ year testimony.
It's been a long time since I studied this, but it seems that this beast is not the same one of Rev. 13:1, which rose out of the sea. The sea is the nations (Da. 7:2,3;Rev. 17:15). This beast is a composite of the 3 beasts of Dan. 7:4-6, and is thus like unto the fourth best of Dan. 7:7. Looking from head to toes as consecutive in time, this beast is the modern revival of the ancient Roman Empire. Its identity is the manifestation of the first of the unholy trinity, the anti-God, IIRC.
All the world wonders/admires/follows after (enclitic of direction) this beast, and because they worship the dragon, that old serpent which is the Devil, and Satan (Rev. 12:7,9; 20:2), the power-giving (Eph. 2:2) anti-Spirit (angels are spirits, Heb. 1:7) who empowers the anti-God beast who came up out of the sea.
But then another beast (allo, of the same kind) came out of the earth (metonomy of "them that dwell upon the earth," who were left behind, so to speak), the second person of the unholy trinity, the anti-Christ, a false messiah, anointed by the Devil I suppose (Dan. 7:8; Rev. 12:11-17), a false prophet (Rev. 19:20).
So, it seems that your explanation of "the" beast is not comprehensive in the bestiary panoply, eh? Worth a little more study, perhaps.
Respectfully --
So, it seems that your explanation of "the" beast is not comprehensive in the bestiary panoply, eh?
Worth a little more study, perhaps.
I think so. You've answered your own question about this second "beast" which, BTW, has no contrary bearing on the seven-year time timetable laid out in Revelation.
Chapter 13 is part of a four-chapter series of parenthetical explanations, background, and overview of the characters and events about to take place. It (re)introduces the "first" beast (13:1) who rises from the sea (probably a Gentile (as you said sea=nations)). It also introduces "another beast" which comes out of the earth (probably a Jew (land often means Israel)). But this second "beast" causes everyone to worship the first beast (13:12), build an image of the first beast (13:14), and forces those who don't want to starve to death to take the number of the first beast (13:16,17).
So in this overview, we see two beasts in a political setting but it is clear the first has preeminence over the second. The second beast is the false prophet who promotes the first beast who ascends out of the bottomless pit (11:7, 17:8) and receives a kingdom (16:10).