Political dissidence in Hong Kong has reached a fever pitch but has been stifled by the Chinese Communist Party’s introduction of a national security law, passed last June. Yet this unraveling in post-handover Hong Kong has been gradual, mostly imperceptible to outsiders. Situated in this context, Howie Tsui’s exhibition “From swelling shadows, we draw our bows” focused on the fantastical yet subversive qualities of mou hap (in Cantonese) or wuxia (in Mandarin): namely, a martial-arts film and literary genre that has been banned repeatedly in mainland China for its anarchic, justice-seeking ways