The Silenced (2015)

Both are about all girls schools with something that isnt being told to the students. They are two of the same genre, both very intriguing until the very end

The Silenced offers a creepy atmosphere and a wonderful and impactful story. It has a very effective OST that builds the tension and realizations in the story. Parasite also deeply includes these elements. They are both psychological thrillers that have exciting storylines that are very unexpected. I think if you started with either of these movies, the other one will offer a satisfying secondary watch as they very much complement each other.

A girl (or two girls, sisters, for ATOTS) arrives at a new home and paranormal shit happens. Also older women treat her (them) like shit. Labeled as horror but neither of them are.

Same director and writer with Park So Dam appearing in both films. Both are set during the Japanese colonialism in Korea and have strong female characters. The Silenced is set in a boarding school while Phantom is set in an isolated hotel. The Phantom is an action thriller espionage film while The Silenced is a horror mystery film. LGBT-coded characters in both films. Both show violence towards Koreans and the horrors of Japanese colonialism during the Japanese colonial period in Korea.

In both movies they have supernatural powers such as extreme force, wound immunity, etc...
The main leads were both manipulated by evil scientificists.

In both movies the protagonists have supernatural powers after the experiments on them (such as extreme force, wound immunity etc... )There are some violent and splatter scenes.

Both are dark movies based in schools and female character driven. The plots are different, but both have great acting and intriguing plots.

Similar vibe, plot line, even character relationships. Both deal with inhumanly strong female main characters (gene manipulated) on a journey of discovering the past/truth.