Isekai Apocalypse MYNOGHRA ~The conquest of the world starts with the civilization 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

I reincarnated as an evil god. Ira Takuto succumbed to illness at a young age and ended up reincarnating in a world that resembled the strategy simulation game, 『Eternal Nations』, of which he loved playing when alive. What appeared in front of him was Atou, a girl belonging to the evil civilization that he used to play as, 「Mynoghra」. The two of them decided to create a new country in this world once again.