Healing the old marshal was just a simple reward for the Ancient God of Chaos, Hunluan, and the World Eater, An Shizhe. The ailments of Long Huang stem from his connection to his crippled beast. Since his beast lost its limbs, he had lost the feeling in his limbs as well, preventing the old marshal from getting up like a normal person. This was actually done intentionally by Huzi, the mythical nine-tailed fox beastman, as punishment for his inability to control his own people, his own race. An injury that human medicine and machines can never heal.