How Did Hitler Develop Such a Humane, Scary Military?

Shree Balram Bhutan says from 1933 to 1939 in just five or six years, how did Hitler develop such a human, scary military? How strong was he when it came to leadership? So Hitler was, first of all, let me just put this disclaimer in case somebody doesn't understand or realize Hitler was an evil person. It was a bad guy. He did horrible things. Now, how did he manage? How did he succeed in building up this enormous military in just this short span of about six years?