Ueshiba had unusual power
He used the same terminology and phrases that exist throughout Asia.
He actually borrowed and directly quoted many internal arts sayings in his writings.
The terminology he used were methods that were known for producing power
Those used them in India/China/Ancient Japan; were also known for unusual power
They all share the same tests- litmus tests for power-that he used
These are all things that can be proven or disproved. But the only way you can do one or the other is by going through a rigorous scholarly process of writing, publishing, and having your work peer reviewed. Not by martial artists, by historians who work in fields adjacent to this line of research. Until that is done this is all a matter of personal belief. There is nothing wrong with personal belief as long as you aren't passing it off as the truth. At best you look like a passionate eccentric when you do that, and at worse you wind up taking advantage of mentally susceptible people, e.g. people who have a tough time differentiating belief from fact, or differentiating knowing how from knowing that.