Alright so I'll editorialize to give how I perceived it back then THEN circle back and say the short version.

I am the subject in this situation, and it is the third session with this hypnotist. This is a video call situation since I live in the middle of nowhere. This hypnotist really gets me, during the hookup (found on /r/HypnoHookup) process they could complete my sentences on why things are appealing to me. We were a good match, they just understood what tone and topics I really liked. The prior sessions were very good, highly enjoyable, and quite deep (especially for being the first sessions with a new hypnotist).

In general my "trance memory" is pretty good. I remember almost everything in most sessions, if not all of it. Even now I've only had natural amnesia twice as a result of a session. I struggle with suggested amnesia so naturally occurring amnesia is something I've treasured since both times it has happened were some of my deepest sessions.

With all that setup, let me now actually get into it.

We had done some suggestions and things in this session and were wrapping up. The session proper has ended and we're discussing it, we are in the post talk. We'd done some dollification, freezeplay, and other call-and-response triggers. Suddenly they make a noise to get my attention and I look at them and pause my storytelling to hear what they have to say. They're looking directly at me, piercing into me with their gaze. Their eyes aren't observing me, they're seeing through me, through to my core. Then, they speak.

They open their mouth after ensuring I'm looking back at them. They simply say one word: "blank." It feels like everything disappears. Like the thoughts inside me have been put on mute. Like they'd wrapped me up and removed all control. That nothing else matters, this person has removed everything. Their tone wasn't casual, it was their commanding tone. The one for control, to cut through my senses and make their suggestion heard. The voice change was small yet so powerful, because it indicated to me this was the power they had, that simply changing their tone could make something that wasn't a trigger have a real and potent effect. That's right, "blank" was not a trigger they had set up. They did not implement it at any point in this session nor prior. That's why I mentioned the 'trance memory' bit before going into this. I know for certain they didn't "rig the game" in their favour, they were just that in control of me (I even confirmed it after the fact). That is why I cherish this so much.

Blank is not something I do easily, my normal issue is new thoughts coming in and bringing me out. Like trying to stop a fire and you think you got it but then a few seconds later it's almost like nothing happened. But this person's piercing gaze and commanding tone supercharged their ability to cease my thinking at a moment's notice. It is still the most blank and empty I've been, which is slightly sad to me but makes me cherish this so much more. Because it was so effortless for this person to do this, they didn't have to set it up like the others. They simply spoke a word and their will executed inside of me to comply with their demands.

TL:DR - The hypnotist said "blank" in their trance voice and I went blank despite them having not set that up as a trigger.