Kylo has no way of knowing that Rokuro would feel the bullets. To him, it's water. A different sort of ability than his own, perhaps, but he compares it to what he can do with the Force. He might feel the emotions of other, but a bullet stopped in midair would feel like nothing other than the concentration it takes to hold it there.

The shield holds. He barely even hears the request for a cue over the deafening sound of the gunfire, but soon enough the opportunity presents itself.

"Now!"