The most important thing he did was planning and executing the deportation of Jew's and being in charge of the Gestapo which were the secret police who protected the Nazi party from any conspirators who were planning to overthrow them
i'd say Heinrich Himmler Hitler regarded Goering as his #2 and despised Himmler.
Most likely Heinrich Himmler.
I'm assuming you mean Reichsführer-SS Heinrich Himmler, the most (in)famous person of that name. His wife was Mrs. Himmler (whose maiden name was Margarete Boden). He also had a mistress (Hedwig Potthast).
Heinrich Himmler was in no way a mystic. He was one of the top leading a members of the Nazi Party. After Hitler appointed him as Commander of the Replacement Party, he was one of the men that were most responsible for the Holocaust.
Heinrich Himmler was one of the most terrible Nazi Party leaders. Hitler placed him in charge of the SS and the Gestapo. Himmler was a chief architect of the Nazi death camps. He was captured after the war but managed to commit suicide before being brought to justice for his war crimes. These crimes were among the most unspeakable crimes in human history.
The Nazi secret police or the Gestapo was headed by Heinrich Himmler. When World War 2 broke out, he was considered as one of the most feared men in Europe and Nazi Germany.
It was not just Heinrich Himmler who hated Jews. Most of Austria and Germany hated Jews. They had this false idea that the Jews were the cause of World War 1 and that they controlled the world. Himmler was just an ignorant, insecure man who fell for a madman.
Most people will agree that Adolf Hitler and his right hand man, Heinrich Himmler were particularly wicked people. The most wicked men of modern times include Osama Bin Laden and Saddam Hussein.
The Nazi official who had the greatest role in supervising the Holocaust was Heinrich Himmler. However, all the members of the High Command were involved. Himmler was in overall controll and oversaw all of the different aspects. The most notorious administrator was Eichmann, he was mainly involved in the process of collecting and deporting people to the ghettos and the camps, which were run by a different department. Eichmann was responsible for implementing the plans formulated by Heydrich and ordered by Himmler (and initially by Goering).
The wikipedia article on Heinrich Himmler gives an overall picture. One of the key people in the National Socialist (Nazi) party, his power grew out of his place as the head of Hitler's bodyguard, the Schutzstaffel or SS, which expanded beyond all recognition. He also had control of the Gestapo, the German secret police. He eventually became the second most powerful man in Nazi Germany, second only to Hitler.
There's plenty of guilt to go around for that, but if you have to bring it down to one person most responsible for carrying it out, it would be Heinrich Himmler.
Their most important thing to them was their gods and religion..