After achieving peace rimuru was stuck doing papaper work for last few centuries was stuck with boredom . Ciel seeing her master's state suggests going back in time to the era when Veldanava created the cardinal world. (I don't own tensura)( I adjusted the story to my liking) if you guys want to read advance chapters go to my Patreon account. patreon : patreon.com/Nauty_Manu