I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too, Vol. 4 (light nove

Right as Yuuya gets roped into the hunt for a traitorous Prince, he encounters a mysterious girl who aims to destroy the entire world! Yuuya will have to push his overpowered skills past the limit to stop her. Complicating everything else, Kaori accidentally opens the door on Earth and stumbles into the other world!