Yeah if you get the fascist party in power and get them enough support in the upper house you roll back reforms and cause a fascist dictatorship. If you are a absolute monarchy if I am mistaken if you get fascist party in power an event will fire where the fascists overthrow your tsar/king/Kaiser and you will become a fascist nation. I have done that process with Russia and Serbia before, but granted I wanted fascists in power in Serbia because try to get tension up to get my cores back wasn't working and I figured having a fascist government would help, it did not but it was fun being the only fascist nation in Europe. Russia on the other hand I was trying to save my absolute monarchy, well actually my total power, because I hate elections sometimes. It was an accident with Russia but I came out with no more rebels, people loved me, and I dominated the Eurasian steps.