A few tags and comments under my "Yuuji can blackflash at will" post are reminding me that one of the issues with people refusing to consider that Yuuji can blackflash at will comes from the fact a lot of people do not understand what a black flash is in the first place. (and even amongst the people who do agree, the comprehension of what a blackflash is is not universal)
It is not a technique, it is not a special ability you're born with, it is the very, very simple, very straightforward act of applying your curse energy into a physical hit within 0.000001 second of landing that hit. It's ALL a blackflash is. No ifs, no buts, no ands- this is what a blackflash is. That is all that it is. The act of (blah blah blah) within 0.000001. second
It is not technically complex. It doesn't need anything to be "activated", not chants, not hand signs. No metaphysical ~jujutsu~ conditions have to be fulfilled. You don't need to have done this or that before you can land of blackflash. It's not luck. It's not a volatile phenomena. It isn't a technique you *use*, it is a physical action you perform. It is the act of (blah blah blah) within 0.000001 second.
What is actually difficult about landing a blackflash is being able to muster up both the extreme concentration needed to manipulate your cursed energy so incredibly precisely, and, therefore, some impressive cursed energy control.
And both said exceptional CE control and said incredible concentration are tremendously difficult to achieve, not even mentioning the mid-fight exhaustion and distractions and the likes. There are a lot more sorcerers who have never landed a blackflash in their lives and never will than there are sorcerers who have. And even within those who have, most aren't able to land more than one a day.
Performing a blackflash is an incredibly difficult thing to accomplish. It requires the ability to "lock in"/concentrate/focus to an almost god-like degree, and absolutely phenomenal cursed energy control. I'm not saying it is an easy thing to do. I'm saying it's not luck, it's not a special ability, it's only a physical action, and I'm saying it's possible to land a blackflash at will if you have a "good enough" capacity to concentrate/lock in and "good enough" control of your cursed energy. "Good enough" here being silly stand-ins for ABSOLUTELY EXCEPTIONAL.
Landing a blackflash at will was considered practically impossible so far because no sorcerer had ever shown a level of CE mastery high enough and a capacity to concentrate to such a degree that they were able to apply cursed energy within 0.000001 second of a hit on demand, consistently. Not because it is physically impossible (again, it's a simple thing) and not because of some mysterious laws of physics/jujutsu that prevent the use of it at will (again, because it's not a technique : you don't *use* blackflash like you use dismantle, you PERFORM a black flash like you perform a high kick or something.)
No one had been able to do it so far because it is a very fucking hard thing to do (and that's understating it. hard is a pretty mild way to describe something no one had ever done before), not because it was impossible. Yuuji has the insane ability to focus to such an incredible degree, and he has a never seen before level of cursed energy control/mastery. Before Yuuji, a sorcerer who could blackflash at will had never been heard of. After Yuuji, it has been seen and done because someone (him) with the capacity for said concentration and said cursed energy control has appeared. :)
bonus "it's a flow state" thing -> no, once a blackflash has been performed you enter a flow state. not the same thing! :)) which is why it theoretically becomes easier to land another one after you land the first one ! because said flow state aids in maintaining the concentration required for precise CE control. that's all !
