Metamorphosis
변신 (original)
A former priest’s family becomes possessed by the devil, forcing him to perform one final exorcism to deliver them all from this evil being.
Starring Bae Sung-woo, Sung Dong-il, Jang Young-nam, Kim Hye-jun, Cho Yi-hyun, Kim Kang-hoon, Baek Yoon-sik, Oh Dae-hwan, Jeong Yun-ha, Jeon Mi-do
It's a horror and thriller movie, and has a rating of 6.9 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Belgium.