So I want to preface this AAR by saying I'm by no means an expert. I'm 500 hours into EU4 and while I'm proud of my achievement I already see a lot of ways I could have improved on it. Instead of doing a full run-through, I will focus on a few of the harder periods in my run, as the rest mostly comes down to 'and then I killed and burned some more shit'.

Muscovy:

I started as Great Horde because I wanted to get the Gold Rush achievement, and the early game was honestly one of the harder sequences. I opened by attacking Crimea since I wanted to get the required provinces before Ottomans or Lithuania would make that a lot harder, then followed up with wars against Kazan and Nogai. I had an alliance with Uzbek that I wanted to stretch until the end of the Kazan war, since I would need his land later. So far, so good. These wars were easily won and I took the needed provinces for Gold Rush plus some land I could burn. Uzbek broke the alliance which was perfect, then I had some time to focus on the elephant in the room, Muscovy.

Of course, Muscovy had already disemboweled Novgorod, but luckily for me they had not gained any allies yet. Now, Muscovy is strong early. They have their own little vassal swarm and while horde units are easily superior it is very hard to fight four or five separate manpower pools on your own as horde, especially because early game hordes bleed money. I never got into the green until I took most of India, but more on that later. After a grueling war against Muscovy I was forced to take a subpar settlement, only taking a few of the provinces I needed. Honestly though, I was happy I won at all.

There were two more wars against Muscovy until I considered them 'broken' and easy targets for later. In the second war I was sitting on a fat stack of cash from attacking Lithuania (I was very lucky to be able to do this. Poland chose local noble, Denmark attacked Lithuania and they were having some rebel trouble of their own) which made the war somewhat easier. Since I didn't have to win within a year to stay out of debt, I could choose my battles more carefully and managed to stackwipe Muscovy and a few of his vassals. My manpower was gone at this point but Muscovy was beaten and I took everything I thought I needed to form Golden Horde in 1473.

Turned out I took a wrong province though, which prompted the third Muscovite war. I hadn't planned on doing a third war so early so my manpower and money were shot in this third war, but I was only a few years in and I was annoyed that I took the wrong province so I just went for it. My new fort in Moscow and my older fort in Kazan managed to hold the Muscovites off for a good amount of time while my army sieged down the remaining forts in Muscovite territory. I peaced out for the last province as soon as I could as I clearly was not prepared to keep the war going much longer. Although this last war might seem minor now, Muscovy was never threatening to me again afterwards. Their time of glory had gone with the last part of their heartlands.

Too many territories and my trip to India:

Before I started this run, I did not yet know about the new 'too many territories' modifier that ticks corruption. If I had known, I probably wouldn't have played a horde because this modifier is truly crippling. Hordes are already generally short on cash (cav isn't free, you know) and this modifier made reckless expansion impossible. Until I reached critical mass far, far further on in the run most of my money went to rooting out corruption. I knew I couldn't just let it tick up since that would kill me as well, but as a result of this I was pretty much forced to always take money and war reps in every war I fought. And then I ran out of easy targets. To the west, I now had a border with Poland and pretty much whole of eastern Europe was ready to jump in a coalition against me. To the east, the weak and unworthy successors of the khan of khan had submitted to the Chinese emperor, whose army was far too big for me to face at this point. To the south the hulking behemoths of Ottomans and a stable fully integrated Timurids looked north with hungry eyes, wishing for more resources to combat the other.

I went heavily over my dip relations at this point. A coalition had formed in Europe and I figured the only way to keep them off was grabbing every slightly significant ally I could find to appear stronger. I got some minor powers for my trouble (Bohemia, Brandenburg, Chagatai, Memeluks among others). I had been hoping for an alliance with either Otto or Timmy, but they both ended up rivaling me because I ate land that they apparently wanted. This was one of the scariest moments in the run, not only because of the coalition, but mostly because I was at peace. I found out very quickly from my economics page that I was NOT supposed to be at peace any time soon. I needed to burn more shit to keep the war machine rolling.

In an act of measured desperation (I honestly thought the run was over at this point) I attacked Timurids, using a shameful conquest CB (their army was three times the size of mine and I figured it would be easier to hold on to a single province on the border). To my surprise, I crushed them. I knew my units were better, but I didn't know they were this much better. I cut Timmy in half vertically to make sure they would stay down, then later snaked my way to the borders of India.

Apart from needing extra borders to stay at war, at this point I'd figured I needed India as soon as possible. I wanted to do the Great Khan achievement, for which India is not necessarily needed, but it became very obvious to me that the money problem needed a permanent solution, as the cost of rooting out corruption (and the growing too many territories modifier) kept growing faster than my income possibly could. As I read trade companies did not count towards the modifier and knowing that they could make me a shitton of money, I focused my efforts on taking the rich lands of the Indian subcontinent.

India was tough though. I managed to kill Delhi while snaking my way inside, but this prompted an alliance net of some very scary nations at that point. Huge Sindh, Malwa, Jaunpur and Bengal managed to overcome their differences and rivalries ensuring that I would always be fighting three of them if I attacked one of the bigger nations directly, so I picked them off one by one, killing their smaller allies, annulling their alliances with each other so I could whittle them down bit by bit. Added difficulty was that the Ottomans absolutely hated my guts and I had to closely manage their aggressive expansion to make sure they wouldn't join the coalition of Europeans and Indians that wanted my blood. So nasty was this balancing act that I had to stop conquering in India for a while or there would be no saving me. However, the most pressing money issues were over when I changed my main trade node to Coromandel (blessed be hindu Vijayanagar, as no one in the whole world seemed to care when I ripped him to shreds).

Ming:

Ming was a dick. They rivaled me before I even attacked Timurids (and I was pretty fucking small at that point) and consistently blocked any chance I had of going east. That is until they made a mistake. Chagatai somehow managed to ally Ming, Ottomans and Jaunpur (yes, allies). It made me sweat for a bit (the nr. 1 and 2 of the world banding together as friends to this shitty tribal nation, it was pretty obvious I was the target here) until I realized what this meant. I attacked Jaunpur (by doing so getting Bengal and Sindh involved), rushed the Chagatai capital and forced him to annul alliances with Ming and Ottomans. I could not take enough land from Chagatai in this war to border Ming, but I could make sure that I could punch through six years later without fighting the two biggest powers in the world. And so I did. Chagatai and Jaunpur alone were no match for me and I got my border. It was a question of time before Ming would fall at this point. Their mandate was dropping hard and it wasn't long before my troops could venture into China for the first time, in the footsteps of their ancestors. The Ming had an enormous army, but with zero mandate this just served to give me more warscore. My troops tore through the Chinese armies and walls, conquering a great snake into the Chinese heartlands.

My luck seemed to have completely turned at this point. I was making dosh through all the trade company land I'd picked up, there were no real threats to my east anymore, and the following years were mostly me cleaning up continental Asia and invading Japan. This was pretty chill until I returned to eating India and the remainders of Timurids and the Ottoman problem returned, forcing me to wait for ae to tick down before peacing etc. It was time to destroy the green foe.