In Khanate Russia, the Horde colonizes you!
I'm just deciding at this point whether to form the Mughals now, or to wait the three years to annex what's left of France and risk getting another succession crisis. My ruler had been on the throne 26 years, making him 41, so the risk isn't huge, but it's there. I've been rampaging through North Germany, the Netherlands, and the Mamluks in anticipation of making the switch.
My last succession crisis was hell, since it was three of them back to back. My first couple of heirs were the same age as the ruler taking the throne, so I ended up getting a 59 year old heir at one point. He ended up taking the throne at 80, and died a month after the succession crisis ended, starting a second and leaving me with a Regency Council and an 11 year old heir. Of course, when the Regency Council ended, that started a 3rd crisis. I had more than enough troops and manpower to handle the rebels, but all the fighting drove my war exhaustion through the roof. It took a lot of very careful management - sending small armies after rebels, and tons of ping ponging - to coax my WE down after that.
Muscowy, Lithuania, Poland, Austria, Bohemia, and most of Italy and Greece are now cored. Turkey will core in the next decade.