Looking at his history, it's easy to see how he became what he was. Strict upbringing, his failure to become the artist he wanted to be, his belief that his time in the military was a "happy" time, only having one testicle, liking to be peed on. As far as his rise to power, all a series of flukes. He was sent in to the burgeoning Nazi party as a spy, but was drawn in by their leader's charisma, and by their playing on his growing racism. They used his natural charisma to play upon centuries of Antisemitism in Germany, and promised to pull the Fatherland out of it's financial slump. When the economy did turn around, they bought in wholeheartedly to the racist regime, and they were able to do anything they wanted.