Dantoudai no Hanayome – Sekai wo Horobosu Futsutsuka na Tatsuki desu ga 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

A “Dragon” appeared from the container that fell in front of Ryuunosuke Dazai–. The malevolently beautiful “Dragon”, Rinne Irako, was sentenced to death as a “Calamity” that could destroy the world and was being transported. However, whether it was a trick of fate, the “Dragon” girl had a miraculous encounter with the boy, and fate was about to change significantly. “It’s to save the world– come on, let’s love each other.”