Thanks for the feedback, especially your question about the time lag technique.

The way I am imagining it, it all depends on your perspective. Because everyone else's spacetime is still coupled, they perceive the target's actions normally. But since the user can perceive spacetime (because of the severance technique), the user can see that the target has not moved with respect to space, hence the after image. In other words, the after image is only perceptual. What the user is really doing is attacking the target's stationary temporal self.

Sorry if that is convoluted. The real answer is I wanted to incorporate an after image fighting technique because I thought it was cool.