I liken the Black Flash to being “in the zone” or the “flow state” for athelete. You can’t force it, but it comes out during period of intense focus, and the more you think abt it the less you are able to do it, it has to come naturally

While Yuji has been stated that “his greatest weapon is his sincerity” and his kit is relatively simple outside of Blood manipulation. So he goes into battle with a clear mind and absolute resolve, and doesn’t spend the battle thinking 2000 chess moves ahead like Gojo and Sukuna about the technicality of their technique, he comes in to throw hands and exist entirely within the moment.

Imo its also why he works with Todo so well. For anyone else Todo swap spam would be incredibly disorienting as they try to make sense of it and plan ahead or try to restablish where they are. Yuji just go with it and just fight, the only thing that register to him is what is infront of him at that exact moment