The rabbit king continued to gather even more speed as it grew faster and faster. Rui would be lying if he said he wasn't impressed by its sophisticated hunting style. In fact, if he hadn't known better, he would have suspected that it was a Martial Art technique.
However, he knew that it wasn't.
It was more so an evolutionary innate ability.
Their entire physiology and anatomy were structured in such a way that it lent itself to allowing them to make extremely efficient and effective applications of their power. At the moment, The rabbit was displaying efficiency of application of power similar to Rui's Outer Convergence.
The difference was that Rui's Outer Convergence was a set of coordinated movements, that he mastered within micrometers and microseconds of absolute accuracy, with timing and placement such that the sum total power generated by the body across the body could be redirected and leveraged in a single point or part.