Oh, my poor wording led to a misunderstanding. I meant that it isn't true that it needs to be released during hellflames. Sorry for that.
So you meant that Brutal Strike B should be activated in Hellflames freeze time.
I tried it that way, but so Brutal Strike B will be the last hit and that hit is always yellow. (But maybe my timing is off?) That was the reason why I tried to do it earlier. And also that way it isn't a supercancel and 214214B was noted as a SC.
When I try it that way, you can tech right after Hellflames. But if I hit with Brutal Strike B first and hellflames right after, he can't. But you're right, he can tech right after hellflames anyway.
Sorry I got it all wrong. When you activate Brutal Strike B right after 2C hits when the opponent is at the top height, you will hit the opponent at the same time when Hellflames hits. So it is released right in Hellflames freeze time as you said. But that's not that easy to time, at least for me. :-)
I'm stupid and just everything I said was wrong.