Arrival
The medical team was stunned by how quickly Rui managed to gain control over his new body. It would have been absolutely impossible to adjust the subconscious and involuntary muscle control of his diaphragm so quickly, but Rui managed to do it nonetheless.
Because of his powerful mind, he was able to rapidly conjure up images for self-hypnosis to reduce the effort he put in, accelerating the mental adjustment rather swiftly. What he essentially did was simply convince his subconscious mind through elementary self-hypnosis, while he sneezed, that air was being sucked out his lungs every time forcefully, causing his mind to want to reduce the force with which it pushed air out to preserve precious air that was already being forced out of his lungs.
This way he drastically adjusted the force with which his subconscious mind performed respiratory function.