Dark Persona is not something you can run away from, it is part of you and your life. What is important is who gets control over whom.
First, let's establish that dark persona is not opposite of you and your hidden personality combined with your mask is what I call Personality Core. It is also important to understand that neither you or hidden you, are good or evil. We should not label humans as good or evil, as all of us has aspects of both. It should be clear that Dark Persona is not your evil side and should not be viewed as it. I am going to label your everyday persona as "positive" and your dark persona as "negative" as it's much better labels then good and evil.
Society expects us to act in a certain ways. Be polite, respect your elders, smile, contribute something, etc. From the young days we where thought to act in such ways that others would like us, however like I said before another aspect of you starts forming when you are learning how to behave in this world. There many theories how personality develops, little they do explore negative aspects in a depth. That is why I find Jung's shadow theory quite fascinating. Still, I am not exploring "his" theory, what I am doing is exploring deep and hidden aspects of complete personality. One of the reasons why negative personality is not heavily discussed is due to the fact that people don't usually want to talk about this stuff. We understand that it is part of us, but we want that side to be somewhere in unreachable location.
Negative is that of calculating chaos. It is like a wild fire, burning with infinite energy, sometimes so big that fire burns the positive. Chaotic and calculating. That burning fire which seems to be infinite and chaotic is what your dark persona is. Nothing less and nothing more. In my last record I used Nietzsche's quote about hero fighting monsters and becoming hero. The biggest monster which you are fighting is you yourself. The negative energy which can consume your positive and burn the house you had build. Eternal struggle between positive and negative is what drives humanity and your soul into deeper meaning.
The two biggest mistakes of controlling negative is how we are suppressing our other side. First, is when we are giving hard suppression over our Dark Persona. It always backfires and it is not pretty when this happens. Other mistake we usually make is that we are giving soft suppression over our Dark Persona and it is all over the place. The question remains how should I suppress the negative so it won't backfire at me? This where it gets difficult, as it is virtually impossible to have complete control over your negative. The best example of people who are at the highest level of such mastery are: businessman, sportsman, politicians and other successful people. They usually can convert negative into positive results. There are two things I would like to suggest. First, listen to yourself, listen to your soul. It is very important what your soul is saying to you as it has knowledge of your conscious and subconscious minds Second, is that you should not fear exploring your dark self, just need to be cautious as it is being of it's own despite being part of you