Hasla 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

In the city of Hasla, if you save 7 lives, you're allowed to murder one person. DoJin dreams of the perfect revenge... by becoming a "Samaritan" in Hasla, the city of blood.