Wushuang

In the early years of the Sui Dynasty, a murder case brought Feng Xiao, the Second Master of the Xie Jian Bureau, and Cui Buqu, the Chief Envoy of the Zuo Yue Bureau, together in a small border town. Driven by different motives, the two engaged in a battle of wits and courage. The usually successful Second Master Feng, however, met his match in a sickly Taoist priest. Moreover, they didn't know until they clashed that this frail ghost had even more disguises than he did!

(Source: Bilibili, translated)