The 70 weeks Prophecy four times refers to an awaited personage at the the end of the 69 weeks and/or the 70th week.
Messiah The Prince in verse 25
The Messiah in verse 26
The Prince that shall come in verse 26
He in verse 27
The standard view among Christians who are Premillennial Futurists (and even some Preterists) has been that the first two are Jesus Christ and the last two the person we commonly call The Antichrist. Chris White however promotes a theory he didn't invent himself that makes each of the four something different. predicating it largely on how unclear it is which of the earlier personages the He in verse 27 appears to be.
However most people reading this Prophecy without a Christian starting point, as well as many Christians who are Preterist, see the clear grammatical logic as saying all four are the same person.
When verse 25 says to await the coming of a Messiah The Prince and then verse 26 says The Prince that shall come logic dictates that it's the same Prince. And if there aren't two or three different people refereed to earlier, figuring out who He is, isn't that complicated.
It's also pretty much unique to Christians to see a Villain in any of the four references. Because you see the "he" after "Abominations" in the KJV of verse 27 isn't in the Hebrew. So the first He is not the one who sets it/them up. That can agree with seeing him as The Antichrist however, because in Revelation while The Image is of The Beast, it's the second beast (False Prophet) that sets it up and enforces it's worship.
I'm going to suggest that the traditional Christian view, and this "only one person is mentioned" view can both be right, via the principle of Double Fulfillment. I've already documented that there are Jews without a Christian bias who see the 70th Week as yet future and separated from the first 69. But I've also argued that seeing the 70th Week as being entirely fulfilled from 30-37 AD is more plausible then my fellow Futurists realize. Recently I've argued that some of our assumptions about how the End Times 70th Week will play out are wrong.
The suggestion that there is a Prophecy which is fulfilled by both Jesus and the Antichrist is certainly controversial. But Solomon was a type of both Jesus and The Antichrist. When doing well he was the near fulfillment of the Messianic Kingdom. But when he backslid, the number 666 was directly linked to him. Samson likewise has been argued to prefigure both, especially by those who see Genesis 49 as implying a Danite Antichrist. Saul could also be viewed this way.
The word "Antichrist" means, false Christ, or counterfeit Christ, or opposing Christ, or replacement Christ, or enemy of Christ. or antithesis of Christ, or opposite of Christ. I've seen several different meanings argued for it, but they all involve Christ, which is Greek for Messiah. Many Old Testament types of The Antichrist were anointed by true Prophets of God (Jeroboam and Jehu, also Solomon and Saul I already mentioned). Jesus refereed to Judas as someone He Choose, and Judas could perform divine Miracles by Jesus authority. Yet he was a Devil and the Son of Perdition.
And at any-rate, he'll need to be able to make Messianic Prophecies apply to him if he'll be a credible Messiah Ben-Joseph.
Given what I argued on those posts I linked to. This would mean his Mortal Wounding is at the beginning of the 70th week. We tend to assume that his Resurrection happens soon after his death. But I notice that there is no reference in Revelation to The Beast being active during the first half of The Week. The first undisputed appearance of The Beast is when he kills The Two Witnesses, and hes' already ascended out of The Pit by then.
I do agree that The First Horseman is likely the man who'll become The Beast. But I've become inclined to view all of the first 6 Seals as being right at the start of The Week, due to my Sixth Seal view and other things.
Maybe the opening of the First Seal has him doing his own Triumphal Entry into Jerusalem, after winning many wars. Doing it maybe even on the same day Jesus did his, the 10th of Nisan. Then he is Crowned Messiah Ben-Joseph. But the next thing to happen is the Red Horseman. Who I argued in that same Four Horseman study could be The Antichrist's killer because of his Sword. And many Christians and Jews will assume that that killer is The Antichrist/Armillus.
My main False Prophet theory wouldn't have it be possible for him to have The False Prophet with him already at this point. But I could be wrong, he could also have a Prophet with him all through those Wars. They could together claim to Christians to be The Two Witnesses, and to Jews that they're Messiah Ben-Joseph and/or Elijah and/or The Prophet like unto Moses and/or the Priest of the order of Melchizedek and/or Enoch. And then people might selectively use the day=year theory to say that The Witnesses being dead three and a half days really means three and a half years.
This deception could fit what Perry Stone (who I respect and consider truly Saved) is predicting. He's saying that The Temple will be under construction during the first half of the week, after Elijah/Witnesses conquers the Muslims. Then The Mahdi will conquer Jerusalem and kill them and stop the sacrifice sin The Temple right after it was just finished being constructed.