I think that (2thess.2;4) probably gives the easiest to grasp(description) of what should "stick out like a sore thumb" about him when he comes. That is if we simply look at the things that he(the beast) is suppose to do as if we were numbering his "ACTS" as they are given to us in scripture he himself(beast),verses the others that mankind have tried to apply those works to,both those incorrectly named as the beast and (the true beast) would be revealed.
In (2thess.2;4) the beast "opposeth"(in opposition to)
Strong's Greek: 480. ἀντίκειμαι (antikeimai) -- to lie opposite, i.e. oppose, withstand and "exalteth"
Strong's Greek: 5312. ὑψόω (hupsoó) -- to lift or raise up, to exalt, uplift "above (all that is called GOD) or that is WORSHIPED",,,So that he(the beast) sitteth in the temple of God,(SHEWING himself),,"THAT HE(THE BEAST),,,IS GOD",,,
So examining the things(ACTS) that he(the beast) will do when he comes he will deceive those/them/mankind into believing that he himself(the beast) is the CREATOR/SAVIOR/GOD of all of "creation",,meaning that in the same like manner Christians view "the Father,Son,and Holy Ghost" as the creator,,he(the beast) will convince most of mankind that he is the "SAME GOD WHO PREFORMED THESE ACTS",,,and they will worship him because they believe he did/does.
I say this because if we examine those we try to calculate/match up with this beast we will find that none of them did these (acts),,meaning Adolph Hitler did not say he was the creator/God,nor does/did those who followed him believe that he was the creator/God. The same should be noted of any of the others that man/men have labeled as the (beast) in the past.
In the (o.p.) the manner of thinking is that Appolyon/Abbadon is the same as (THE BEAST) and that Adolph Hitler is the same ect. but in (Rev.9;4),,BEFORE the one called Abbadon/Appolyon comes(rev.9;11) the MARK/666 and the Mark of god has already been received(Rev.9;4),,,so "Appolyon/Abbadon" rises/comes after the two horned beast(rev.13) and after the wounded head(beast) rises(rev.13),,,
Abaddon - Wikipedia, the free encyclopedia