If they are the same, then Daniel, Paul, and John are not giving us separate prophecies about unrelated individuals. They are each revealing another part of the same picture—its origin, character, development, activity, and eventual judgment.
They are the same individual which he will appear in the future.
Which God is giving the world 7 years to have their way and go against the truth.
And when they follow the antichrist and take his mark then salvation is no longer available to the world and God will end sin on earth.
Daniel 7:7 After this I saw in the night visions, and behold a fourth beast, dreadful and terrible, and strong exceedingly; and it had great iron teeth: it devoured and brake in pieces, and stamped the residue with the feet of it: and it was diverse from all the beasts that were before it; and it had ten horns.
8 I considered the horns, and, behold, there came up among them another little horn, before whom there were three of the first horns plucked up by the roots: and, behold, in this horn were eyes like the eyes of man, and a mouth speaking great things.
Daniel had a vision of 4 beasts, Babylon, Medo-Persia, Greece, and the Roman Empire.
These 2 scriptures is the Roman Empire.
Which 10 horns come from them the world divided in to 10 sections with a leader in each section.
The little horn, antichrist, comes from the 10 horns.
12 As concerning the rest of the beasts, they had their dominion taken away: yet their lives were prolonged for a season and time.
Babylon, Medo-Persia, and Greece will never have physical dominion again.
23 Thus he said, The fourth beast shall be the fourth kingdom upon earth, which shall be diverse from all kingdoms, and shall devour the whole earth, and shall tread it down, and break it in pieces..
26 But the judgment shall sit, and they shall take away his dominion, to consume and to destroy it unto the end.
27 And the kingdom and dominion, and the greatness of the kingdom under the whole heaven, shall be given to the people of the saints of the most High, whose kingdom is an everlasting kingdom, and all dominions shall serve and obey him.
The Roman Empire does not lose their dominion until Jesus puts down the world.
Which they will devour the whole earth, tread it down, and break it in pieces.
Which is by way of the new age christianity(1 Timothy 4:1-5; 2 Timothy 4:2-4).
So this is in the future when the little horn appears.
2 Thessalonians 2:8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved.
11 And for this cause God shall send them strong delusion, that they should believe a lie:
12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
This is at the time that God is going to end sin on earth.
Which in Revelation 12 the devil's are cast to earth which they deceive all people who do not love the truth which is the strong delusion God will send them.
So this is in the future when the man of sin appears.
1 John 2:18 Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
2 Thessalonians 2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
The antichrist is to come in the future but is already working in the world.
For the mystery of iniquity already works in the world and the man of sin will appear in the future who will be Satan inhabiting a human body and represents iniquity for he is against God and deceives the world.
The antichrist is the man of sin, and the little horn who will appear in the future when God is ready to end sin on earth.