So, I was playing as Bulgarian king, minding mine own business. When suddenly event involving Mongols appeared. It gave me 5k gold, bunch of mongol nobles came to mine court and 120k Mongol army of mine appeared near the Caspian Sea. Army that did not count as raised levy, did not require upkeep and did not suffer attrition. By just using them I crashed and burned entire Byzantine army in mine independence war. Just to be cleared, Byzantines were having one of the strongest empires I have seen in this game. Conquering almost entire Middle East, Egypt, half of north Africa and southern Italy.
Has anyone else got this? What is point in this event? Personally I found it hugely overpowering. When I crushed Byzantine all of the Mongol army remained at mine command. Loosing no more than 30k men. So I had some 90~k super army that was free, and ~7k gold in reserves. Didn't even try to wage another war. Just quit that game.