Yan Xishan was arguably the most pro-Japanese among the Chinese warlords of the era. Thus during the Second Sino-Japanese War, the Japanese saw the rift between Yan and Chiang Kai-shek and had multiple times asked Yan to cooperate with them, but he refused and even contributed his part in resisting the Japanese invasion. So what if Yan accepted the offer of collaboration and became the Wang Jingwei of ITTL? Would Yan have a chance to apply his modern ideas to other parts of China, albeit with restriction by the Japanese?