Kaede and Voört were working on a molten lump of metal when the outmost layer exploded in a long cascade of bright hot flakes. Enicya shielded herself behind the workshop's entrance door. Voört was tough enough to withstand unscathed that level of damage. As for Kaede, if he still had both arms he would have taken twice as many second degree burns.
"Nzanima!" shouted Nicya enraged.
"Towld yo'it'dnt worke" smugly remarked Voört.
"...It absolutely can work." concluded Kaede. The other two lambasted him.

While treating Kaede's wound Nicya demanded to know what the heck were they doing, and Voört explained something barely intelligible which could be summarized in both forging and refining a piece of copper at the same time. For someone who could barely control a Three Shaded Flame after more than a whole day of refining it, she couldn't quite put her finger on how she felt about what she just heard. As she established, in cultivation refining means becoming one with something, and the best path towards that goal is by changing oneself rather than bending the will of the thing. In this case Kaede had to become that lump of molten copper? "Just why?" she asked.
"Well the practical applications could be many, from ejecting the impurities within the metal to weaving formations into the item. It would be pretty much like forging artifacts."
Nicya was done, both listening and patching his wounds. "You're an idiot. I'm not going to say next time I catch you doing something stupid I will kill you myself. Next wound I happen to see on you will be your last." Then, she turned to Voört: "And if I get even the slightest reason to think you have anything to do with it I will raze this place to the grond."

Kaede felt seriously stupid. It was the second time someone warned him to take care of his body, but his manifest inability to feel pain was such a sly liability he hadn't taken it seriously enough. Previously he considered Tebonai's suggestion to become a guild receptionist just because it was a quicker and easier way to access the archives, but now? It finally dawned on him that pain was a reminder of death, and he could only imagine how much pain would a normal person have been in, in his stead. Not to mention he made a promise to the owner of that body, but at that moment Caedith's greatest bully was Kaede himself.
And, because he feared of forgetting this feeling, he sat down and refined it.