WI: Cesare Borgia conquered Italy (AC: Brotherhood)

I've said it plenty of times before, but I find Cesare Borgia, in my personal opinion, to be one of the most fascinating figures in Italian history. He was ambitious, even ruthless, yet intelligent and a very effective military commander and administrator, proving to be quite preferred by the citizens of his short-lived Duchy of Romagna, then the previous vicars, who were cruel and petty. In my opinion, he's a complicated and complex character, who fell from grace was due to bad luck after his father's death...

Then we have Cesare Borgia from Assassins's Creed: Brotherhood. Now, I like AC Brotherhood... but the portrayal of Cesare Borgia in the game, while still ambitious and ruthless, is also portrayed as Templar, an incestuous manchild who murdered his own brother, and later killed his father, in the while for own delusional aggrandizement and ambitions to conquer all of Italy and even Spain, using the Piece of Eden to do so. It's not a fair portrayal, but one that works for the story in AC Brotherhood.

I've talked about Cesare Borgia in various threads beforehand, but I want to talk about this Cesare Borgia,

What if Cesare Borgia (The one in AC Brotherhood; Not real-life Cesare Borgia) was successful in conquering all of Italy, using the Piece of Eden. The PODs would be Ezio's death in Monteriggioni, all the while the Borgias eliminate the remnants of the Assassins in Rome, and then the rest in Italy. He also takes care of his father Rodrigo Borgia and gains control of the Piece of Eden, using it conquer Italy (Romagna, Savoy, Venice, Florence, Milan, and Naples/Sicily. etc) and unite it under the Borgia banner.

With that out of the way, how would this Borgia Italian Empire look like? How would the rest of the kingdoms such as Spain, France, the HRE and the Ottoman Empire react to this? How would the other Templars react?