The Exorcist Expert is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

When I pulled the book of forbidden knowledge from the shelves of the city library, I watched, helpless and terrified, as my life blasted off into another railroad of crazy eating words. And along the way, I ran over some mantis-ridden trash.