I would convince him to make scientology based on science and eugenics. Dianetics will be the science to find out if you're pure Aryan or not and there is space aliens but they are German survivors of the Second World War who carry the nationalism pride of Hitler's Germany. Hitler's main plan with Von Braun was to create a space agency to fight the jews who work with the alien emperor, Xenu. Xenu created the Jews in order to oppress everyone in his eyes. Hitler knew about this and made it his primary objective to wipe them out which made Xenu afraid and sic his jews and their slaves (us) onto him for rebelling against his power.