Have you actually faced a live blade ?
My son Rik has - when a guy burst in on a party he was at. there was wall to wall poop until Rik disarmed the nutter without injury to himself or anyone else.
Toe Breathing in MMA
I remeber reading that story of your son somewhere. Firstly I would say I can only admire such an act. For me it's an example of true warrior spirit and is humbling to see. If I was to carry that with me at all times in all situations that would surely be a dream come true.
As to have I ever faced a live blade? Well yes.
In training now and in the past intensive training with my old teacher we of course used the bokken. However, at one time in that past where I seemed to be stuck, I was continuing to try to do a particular technique from a fast attack, he brought out his real Katana.
He unwrapped it and faced me. I was not scared and I was ready. In my mind I trusted him and knew he would cut through and that his sole purpose was to teach me something I wasn't getting. Low and behold he acknowledged me with a bow and handed me the sword. He then asked me to cut, to do shomenuchi on him.
I nearly feinted. I trembled and turned turned to jelly. On regaining my composure, seeing all kinds of thoughts pouring through my mind about what if...... I finally managed a solution which was to cut with intention and yet stop before I hit him. I did. He didn't move. He merely looked at me smiling and told me'Now if your ready and would care to stop f'ing about would you kindly do what you're meant to do. I did, I ended up flying through the air and there he was holding the sword. Thus I found my real barrier right there.
Funny thing was he then called for multiple attacks on me and they were now no problem. Thought you might enjoy that as your question took me back there.
So live blades in life I have faced yes, all in the forms of knives though. Oh, plus one pair of scissors ha ha.
So I'm not saying if someone was threatening me with a samurai sword I would look at it as nothing, far from it, but if god forbid it happened I know through my training what I should do. As always you never know how you will react in the real situation. I find generally I go calm and focussed in real danger though and that's about as much as I can say.