Unless these powers were not so otherwordly but he sold them as if they were.
No not just him...them. And that's my point. People really buy this stuff.
It is worth noting the prep work and grooming that goes on with these somewhat odd teachers, loooong before they step on a mat. It is easy to take real and actual skills, combine them with an ukemi model and mental manipulation and come out a boy wonder. It's a twice told tale that still sucks in otherwise solid people.