The Kingdoms of Ruin 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

Due to the Gear Expansion, witches who had been friends with the people become unnecessary. Humans, who were afraid of unscientific power, begin a witch hunt… And a human boy who has his beloved witch killed becomes the “Wizard of vengeance”.