Ok, so let's talk about the political power. Who took over the political power?

Will the papacy, who lost the political power as the deadly wound, will it regain political power. So who took over it after it lost it? Who caused it to lose that political power following the same pattern as Babylon <= Medo-Persia <= Greece <= Rome <= Papacy <=?

Will the papacy, who lost the political power as the deadly wound, will it regain political power?
Yes -- it will regain it's primacy over the nations.

Rev 13:3-4 his deadly wound was healed: and all the world wondered after the beast. And they worshipped the dragon which gave power unto the beast: and they worshipped the beast,

Babylon (head of gold, lion)
Media Persia (chest of silver, bear, ram)
Grecia (bronze, leopard, he-goat)
Rome (iron legs, beast, huge horn)
Divided Rome with papacy (ten toes of iron and clay, ten horns with one stout horn, huge horn)

And THAT'S IT!!!!
There are no more kingdoms in the progression of kingdoms in Daniel 2, 7, 8.

Who took over the "political power" after the papacy lost it?

The "ten horns" (you'll find ten European countries again, who were under papal supremacy -- Tuscany, Austria, Bavaria, Bohemia, Prussia, Portugal, Spain, France, Britain, Netherlands and more) no longer allowed the papacy (the stout horn) to tell them what to do.

One of the ten horns (France) got the notion of uniting the ten horns under their banner -- the story of Napoleon --
and he set out to do so with considerable success at first, including his conquest of Italy and the papacy, but he met his "waterloo".

So the papacy's political power was initially removed by one of the ten horns -- France under Napolean -- the story of ambitious princes arising among those ten horns trying to unite the ten horns has always failed. Daniel states "they shall not cleave one to another".

All through Papal history, the papacy saw to it that Italy NEVER became a single country. That way the papal throne of political power was not in danger of being overpowered by the local state. The Italian peninsula in 1790's was not a single nation but rather lots of smaller countries, some of them under the jurisdiction of Spain, a couple others under Austria, a few under France, etc..

Italy was one of Napoleon's chief conquests in Europe, and he became master of the Italian peninsula. He made some major changes in their political picture, setting up a republic with himself or a son being the "president". But after Napoleon passed off the scene, 1815, the Congress of Vienna freed Italy from French domination. Austria, however, still exercised considerable power in Italy for several more years. Italy struggled to gain it's independence from members of the other ten horns.

In 1859, Italian nationalist leaders were able to drive the Austrian control from Italy and united many of the smaller states. The Kingdom of Italy was proclaimed in 1861; Venetia was annexed after the Austro-Prussian war in 1866; and Rome was taken from the Pope in 1870.

So basically -- the answer to your question --
the ten horns no longer accepted the "stout horn" as being able to frighten them into compliance with the threat of "excommunication" etc. And they took the political power to themselves.

So the political power was taken away. The papacy will get it back in the future, but for now someone else has it. Interesting, I have heard the thought that the papacy was still in control but had puppets for distraction. Different way of looking at it, I guess.

With the 10 horns, Arius comes to mind. Who was he, where was he from, what part did he play in the scene?

Well, we are being broken up by people bringing in Islam to replace the Papacy. It is a 'red herring' as they say, just to deviate enough to throw us off and bring disunity and confusion. Here is a study my friend Amo showed me by Louis F Were that he had found to be very informative. The author is hitting the mark, and I like what he has in the beginning..

"Concerning the interpretation of Daniel’s previous prophecies Seventh-day Adventists are united.,But the same unity is not maintained concerning the interpretation of Daniel’s last prophecy – the reason for this is because the concluding portion of Daniel 11 (vs. 36-45) is not interpreted according to the same principle by which the previous parts are interpreted. When God’s people apply this principle consistently, the unity manifested concerning the earlier prophecies of Daniel will also exist in regard to this last prophecy. When this time comes as it surely will – there will be seen among us “a great revival,” that “great revival” which the Lord’s servant declares will come “when the books of Daniel and Revelation” are “better understood.” Testimonies to Ministers, p. 113." http://the2520.com/PDFs/KingOfTheNorth-Were.pdf

Notice he also states "A right understanding of Daniel 11:40-45 concerning the ending of the king of the, north at Jerusalem will be found to throw a flood of light upon other portions of the Scriptures that are vital to the Third Angel’s Message: it will be found to contain a thrilling message of triumph for the people of God....

Our attention should be arrested by the fact that in the scores of places where the Lord’s servant refers to Daniel’s prophecy of the deliverance of God’s people, greatly enlarging upon the theme in her graphic descriptions of that great event, she does not make the slightest reference to the ending of Turkey!

For instance, read chapters 40 and 41 of “Great Controversy” concerning “God’s People Delivered,” and observe at this deliverance of the people of God is described in connection with the judgments which fall upon Babylon. In “Early Writings,” pp. 282-285, in the chapter, “The Time of Trouble,” God’s servant invariably speaks of the deliverance of God’s people in connection with the enforcement of Babylon’s false Sabbath and the attempt to slay the Lord’s people for their loyalty to the Law of God. Not the slightest reference is made to Turkey’s doom! Yet in Daniel 11:45; 12:1 the ending of the king of the north is mentioned in connection with the deliverance of God’s people! The obvious conclusion derived from this association is that the king of the north is responsible for the “dangers” and “conflicts” of the church, and that it is his evil work against the church which necessitates the Lord’s intervention to bring “deliverance” to His people.

As the king of the north does the same work as the Papacy there can be but one conclusion, namely, that the king of the north refers to the Papacy. Thus we see why John the Revelator and the servant of the Lord describe “the final, deliverance of the people of God” while describing God’s judgments upon spiritual Babylon. Daniel, John, and the Spirit of Prophecy are in perfect agreement!"

Tim R isn't saying the King of the North is Islam. He agrees with James White that it is Rome and Rome's allies, the fallen Protestant churches. James White and Rosenburg are in complete agreement on that point. There is no disunity or confusion there.

Regarding who the king of the South is at the end of Daniel 11, as I recall White was cautious on that point because he wasn't sure. Tim suggests Islam. And since Tim is not pushing the idea as a test, it shouldn't cause division. It could be Islam and communism. It could be primarily communism but given the literal meaning of the chapter, Islam fits quite well I'd say.

When it comes to unfulfilled prophecies like the identity of the king of the south we have to be humble and admit we don't know for sure. And even regarding the mark of the beast we've been cautioned that there is more to learn on that point. Having a diversity of gifts means we're going to see things from different angles. The good new is that unity and the flood of light will come as we are sanctified in the truth. It is sanctification in our daily lives that makes it possible for the Holy Spirit to unlock the sealed prophecies to the church and bring a flood of light. May God help us is my prayer.

The view that the papacy is the King of the North is a satanic deception.

I know Catholics would agree with you, as well as many Protestants with their more congenial interpretations as they clasp hands with Catholicism.

They all now look with distain at former interpretations which held the idea of the Papal power being the "little horn" the "beast" the "whore" "the king of the north" and they would agree with you that those views are a satanic deception.
(That's not saying you dispute all those symbols, yet your strong statement is one peg in going down that path)

But what is the REAL deception that is about to sweep the world? All this, peace, peace, the papal power is for good not evil, that is a popular sentiment in the Christian world today, is just disarming people so they won't resist the great deception.
This is not to disparage any Bible Christians but to warn them to look to Jesus NOT to religious world leaders.

you read too much from you imagination into my words.

The king of the north is Apostate Protestantism under President Trump and soon to be under President Pence.

The King of the South is Iran, soon to be at war with the US.

And this unity of which you quote below is not the unity that you promote that believes and teaches error. Only those who unlearn error and embrace truth will be in the unified Church when Jesus comes. But the Laodicean mindset is so strong that too many have need of nothing and nothing is what they will get: To those who have more will be given and to those who lack their little bit will be taken away.

The king of the north gathers up Protestantism that has given up the protest and returned to the "father" pope. Remember the speech of the pope Francis where he quotes Malachi 4 in a video played at a protestant gathering in the USA and everyone cheers. The speaker keeps saying the "protest is over" as if that was a great and wonderful thing?

Remember the News saying"
"Another Ecumenical Breakthrough: Swedish Megachurch Pastor Converts to Catholicism"

Now ask yourselves a question -- how does converting to Catholicism relate to "a breakthrough in Ecumenicalism"?
Obviously ecumenicalism is a return to Catholicism -- exactly what prophecy said would happen.

Don't you remember the pope's visit to America, to the White House etc, and all the red carpet and speeches in high places, with some rather symbolic moves.

"God's Word has given warning of the impending danger; let this be unheeded, and the Protestant world will learn what the purposes of Rome really are, only when it is too late to escape the snare."

The pope has always relied on powerful nations through which it achieves it's power. Prophecy shows the end time world power the papacy will use. Whoever controls America controls the world -- and we read in GC 581 that Rome is gaining huge influence in the legislative halls, in the churches, in the hearts of the people, strengthening her forces to further HER OWN ENDS, and she will strike.