My take on the ending is after Ma Zhai Xing's death, Chu You Wen brought her back to the mountains and buried her there. He then lived on for six months before passing and following her in the afterlife.
Everyone in the comments is excited for Wang Yibo or Song Qian but I am excited for Huang Xuan. He was amazing in Tribes and Empires: Storm of Prophecy despite the horrible ending. It been a long time since he act in a historical drama. Can't wait to see him in this drama.
https://dramapanda.com/2020/11/day-and-night-sequel-is-off-the-table.html