What is the ending of the Korean drama Possession?

The suspense drama Possession is directed by Cui Daoxun, written by Park Xijiang and starring Sae-byeok Song, Gao Junxi and Yan Zhongxun. The play tells the story of Jiang, a criminal policeman with long-term intuition and reversal ability, and Hong, a woman born with psychic ability, who works harder than anyone else to lead an ordinary life, jointly pursuing the evil soul possessed by people and committing crimes.

After reading the synopsis, I thought it was a crime and criminal investigation drama. After reading it, I found that this is a love drama, or a drama that wants to write selfish love into great love. The screenwriter is really awesome, and all the plot trends are not what I expected. Without ten years of cerebral thrombosis, I can't write such a plot.

The IQ of male and female hosts is 0, and they know that their opponents are ghosts, and they don't prepare any equipment. Are there any geographical restrictions on spells or something? Can I only use it at home? When people with a single surname go to a psychic to summon the soul of Huang Datou, they all know that the protagonist will not prepare anything with sticky rice for self-defense.