Rui left Kane to his own devices as he began spending his days mastering his new sense. He was initially having a little bit of difficulty with the new sensory technique that he had come up with. The reason was simple.
Sensory techniques required the most amount of training resources compared to other techniques in his experience. This had been true for every single sensory technique he had ever mastered in his entire life starting with the first one with Seismic Mapping all the way to his latest one. All of them he had mastered using the special sense sealing esoteric technology of the Martial Union.
Did that mean that it was impossible to create a new sensory technique without it? Of course not.
But it most certainly showed Rui how effective some of the training that Rui had undergone with the Martial Union's resources could be.