A huge, gaping hole in this theory... 90% of historians do NOT think Adolf Hitler was secretly a jew. He knew a jewish girl when he was young, and was very fond of her, but she and her family rejected him. This was believed to be the catalist for his hatred of Jewish people. And since you are trying to use Buddhist material, you should know that reincarnation includes punishment for past-life actions. Everything he did, every evil vicious order he gave, would earn him a life as a cockroach. Probably about 100 generations worth of cockroaches, before he comes back as an ordinary farmer or factory worker, then MAYBE a couple of deaths later comes back in a very high position.