The Restless

Between heaven and earth, where love became a legend.

Wikipedia: "The Restless is a 2006 fantasy South Korean film directed by Jo Dong-oh, starring Kim Tae-hee and Jeong Woo-seong. The films Korean title literally means "Midheaven".

In fictional ancient Korea, Yi Gwak is a demon hunter who lost his lover, Yon-hwa, and colleagues of demon hunters in the past. He enters the Midheaven, a transitory place for spirits, only to find the spirit of Yon-hwa who has forgotten about him. His deceased former mentor, Ban-chu, masterminds a demonic rebellion in Midheaven, wishing to invade the living world."

IMDb: "It is AD 924, at the end of the United Shilla Dynasty. Continuous riots sweep the land ruled by a corrupted government. Evil forces are rampant and malicious demons roam the land. YI Kwak, born with the powers to see spirits, joins the royal demon hunting squad, 'Chuh-yong-dae' after losing his fiancée, Yon-hwa to evil demons. YI Kwak excels as the most talented warrior of Chuh-yong-dae and the royal squad seems to gain momentum as powerful fighters against the forces of darkness. Then one day, YI Kwak drifts into Joongcheon, the world of the dead through a strange shrine. Joongcheon, the intermediate world between Heaven and Earth, a place souls remain for 49 days, preparing for reincarnation."

You need the really big screen to appreciate all the fight scenes and special effects.