Transformniks don't believe in universalism because they believe that Satan and probably others will never repent and accept God. They also don't believe that permanent separation from God is never justified. There are Transformnik mystics share the belief from Christian and Muslim mystics that Heaven and Hell are states of being that people create based on how they lived. The default state of Hell is permanent and it's only through reform and purging of certain sins that certain people and spirits can be released from Hell.
The most severe sins as described in the Tome (the holy book) are polytheism and idolatry, atheism and social dysfunction and those who lead people to these sins. These sinners are punished the most severely and are usually considered beyond any salvation.
This is not an official part of Transformatsiya but is something that mystics have theorized. There are two possible methods of redemption for severe sinners. One is to appear in the dreams of a large number of people who would be damned and push them towards salvation. The other is reliving a recreation of one's life repeatedly with no prior memories while in the recreation. They continue reliving their life on repeat with the same initial conditions until they get it right. Usually it requires some major black swan event of free will. Each time they come out of the recreation, they have all of their prior memories returned, including memories of previous lives in the recreation.