The Mystic Nine Side Story: Flowers Bloom in February 2016 on netflix

The side story narrates the effort of relocating a cultural relic safeguarded beneath an ancient tomb during the Sino-Japanese era. Er Yue Hong undertook this mission by approaching the tomb which on the surface is a heavily pre-occupied Japanese army base. Tapping his skills for Chinese opera and utilizing his connections, he performed as an opera singer while fighting off the Japanese soldiers on the other. With his wisdom and bravery, he strives with his might to recover the relic.