So I just have to create an overpowered empire in CK2 and then roflstomp my way through the other games
Yeah, pretty much.
So.. I tried my imported game where I made an independent Frisia and conquered Ireland starting as the duke of Flanders but it was pretty boring...
I had no real goal, and my neighbors France and the HRE were out of my league to go to war with (England was also part of the Holy Roman Empire in this game). I tried taking Scotland but it was just boring because of the lack of challenge..
So, I started a fresh game as the Byzantine Empire fully expecting to get wiped out by angry Ottomans within the first three decades... Only that didn't happen, I wiped them out!
You start the game with Constantinople, two tiny provinces in Greece a pitiful army and a navy that's not even worth mentioning. I like starting as a underdog, so that's good news!
The island of Rhodos is a core of mine but I can't touch them directly because its Independence was guaranteed by Venice, but I see Greek rebels pretty much ready to rise against them and join me so I discreetly start trowing money at them, they revolt and join me within two years.
Meanwhile me and my ally Serbia start and win a war with Bosnia I end up with three more provinces near the coast and Serbia annexes the rest. I also successfully take over Cyprus after they have a peasant revolt and their independence is no longer guaranteed by the Mamluks.
I spend some time building my army for the coming war with the Ottomans and fund Bulgarian rebels in their territory.
Finally in 1463, that's 19 years after the start of this game I see the perfect opportunity, the Ottomans and Mamluks are at war with each other and Bulgarian rebels are laying waste to the Ottoman Balkans.
I attack the Ottomans and suddenly an army of Greek patriot rebels rises up in Athens and they join me in the war. With three large (rebels and mine) and one small army in the Balkans it doesn't take long until all Ottoman troops there are wiped out. Their armies in Asia minor and Anatolia are tied up in the Mamluks war, I am winning.
But then! disaster, the Mamluks accepted a white peace and Hungary invaded Serbia, I abandoned my former allies and kept my army back while the Ottoman armies first took Constantinople giving me a -30 war score and then destroyed the Greek rebel army. They won but were severely damaged I attacked them and wiped what was left of their armies of the map.
They tried turning the war with new armies freshly recruited from their provinces on the other side of the Aegean Sea but I had dealt a death blow, they were on their knees and begging for peace.
After nine years of fighting the Ottomans gave up four provinces in the Balkans to the Bulgarian rebels, one to Serbia (They lost their war with Hungary but didn't lose any land) five provinces for me and kept their capital in Edirne.
I build up my empire after that and took Crete, Dalmatia, Corfu and Naxos from Venice. Fought and won a war with Serbia where I took a few provinces and released Bosnia.
I wait a few more years, the Mamluks take a large part of land from the Ottomans in a new war, they never recovered from their war with me. At this point the game tells me I have the second largest navy and seventh largest army in the game, with that thought in the back of my head I take Asia Minor from what's left of the Ottoman Empire.
And here I am now, the underdog Byzantium has pretty much total control of the eastern Europe and my navy dominates the Mediterranean and Black Sea.
I officially like EU 4!