Meridian Myelination

myelination noun1. the process of forming a myelin sheath2. the production of a coating of myelin around an axon

Shang Qinghua (Airplane) and Shen Qingqiu (Jiu) and captured while on a mission. Things go wrong, and Shen Qingqiu watches with horror as his martial brother becomes something other. Not demonic or even heavenly, but certainty filled with power. Shen Qingqiu can do nothing to stop the thing from wiping the small demon clan from existence, nor can he stop the being from touching his cheekbone and rendering him helpless. He does not know what it wants from him, but the way it strokes his skin and coos at him can mean nothing good.

Or: With Sang Qinghua having full author access unlocked temporarily, he wants to do right by his poor little Black Jade, and so he uses his limited time and powers to try and nudge Shen Qingqiu onto a more virtuous path. It isn't easy with how stubborn his little scum villain is, but even if none of his words get through to the man, straightening out his meridians and covering them with a myelin-like sheath would certainly be enough to change something. Even if it doesn't get the man his happy ending, Xiang Fei will have tried.