The Call (2020)

It's not exactly horror, but more of a thriller movie, "The Call." Personally... Jeon Jong-seo's facial expressions... were so scary lol Seo-yeon (Park Shin-hye), who returns to her long-abandoned childhood home, accidentally makes a phone call to Young-sook (Jeon Jong-seo), who lives in the past, 20 years ago (1999), and they become friends. Young-sook lives in an unfortunate family environment, suffering abuse from a shaman referred to as 'Shin-eomma'. Seo-yeon tells Young-sook about tragic past events, and at Seo-yeon's request, Young-sook prevents a fire accident that occurred in the past, saving Seo-yeon's deceased father. With her father alive, the present changes for the better, but Seo-yeon learns that Young-sook will kill Shin-eomma in 1999 and transform into a brutal serial killer. Having learned her future, Young-sook brutally turns on those around her, harming them, and as the past and future intertwine, she begins to threaten the current lives of Seo-yeon and her mother. You can watch it on Netflix lol