Ukemi from Katsurada Shihan 

I'm sorry, I thought that was implied. No?

No worries. I was looking at videos on training on ukemi. Saw the title and thought it is about him showing us how to take (receive) ukemi.

What should he use?

at his level he should only use Ki and Center line power, kokyu ryoku and chusin ryoku, in that way he shows more higher and advance level openly to his audience (in his case this seminar).

+AikiTom76 I can't remember where, but I once read to defeat an opponent, beginners use strength, those with a little experience use speed, those with a lot of experience use ki, and those with mastery use their opponent's own mind. So with all those expressions of Aikido, which ones should a sensei teach on the mat?

There is a lot more going on here than just speed and strength. I also made (incorrect) assumptions before attending a few classes with Katsurada sensei in Feb ‘18. His instruction was excellent. What I thought I saw in this video was not what he was utilizing... he has speed, strength, whole body connection, timing, footwork, softness, etc. He has background in Daito Ryu, kenjutsu, several schools of karate, +. This clip shows a small snippet of his execution on a particular day. That’s all.