I Have To Be A Monster is a Manga/Manhwa/Manhua in english 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

Xiao Qiu, who quietly guards humanity with his own strength, is misunderstood by everyone. Having experienced a depressed life and being reborn, he embarked on the path of becoming a bloodless and tearless monster. “Saving mankind, what does it have to do with humanity”