Sheep’s mask
Efforts Never Betray
Justified Murder
Save Me
Chasing Tails
the savior's time
PIGPEN
Bastard (hwang Youngchan)
Sweet Home
Shotgun Boy
Ajin (manga)
Devil's Editing
Mode II
Mirror Game (unique plot)
Dr Frost (this one is good)
My Student Can't Be a Psychopath
pumpkin night
Strangers from hell(completed) - There is around 80+ chapters but it’s not completed on mangago(only around 40 chapters) but you can read it on Webtoon. If you are patient enough, you can read for free using daily pass. The story is really good that there is already a kdrama adaptation. The story kept me on my toes till the end. Do give it a try!
Mangas :
Funohan
Taxi
Brutal: Satsujin Kansatsukan no Kokuhaku
Itou Junji Kyoufu Collection
Crime Puzzle
Character
Tomie
Chiller (read this one on webtoon for the effects)
Ajin
I recently got into reading horror/psychological mangas, any recommendations? Preferably completed ones or ones that update regularly, thanks!