Spoiler
Yes, the girl that died at the lake was one of her reincarnation, FL is the next reincarnation, got info from here https://www.novelupdatesforum.com/threads/a-mermaid-trapped-in-my-lake-%EB%82%B4-%ED%98%B8%EC%88%98%EC%97%90-%EA%B0%80%EB%91%94-%EC%9D%B8%EC%96%B4-r-15.144926/page-2
Spoiler
Yes, the girl that died at the lake was one of her reincarnation, FL is the next reincarnation, got info from here https://www(.)novelupdatesforum.com/threads/a-mermaid-trapped-in-my-lake-%EB%82%B4-%ED%98%B8%EC%88%98%EC%97%90-%EA%B0%80%EB%91%94-%EC%9D%B8%EC%96%B4-r-15.144926/page-2
Well mainly because her other reincarnation came back during a time of his mourning period and people who are usually left alone for so long by themselves end up crazy. But since it cave to the present, a lot of people ended sing the mansion and wanted to purchase it which prompted unwanted visitations, causing the man to go in a frenzy killing anyone who entered. Until he saw the FL again after a long time after her reincarnation died prior.

i’m lowkey confused…