Historias de Rimtan

This is my first story, and it's an anime crossover between that time I got reincarnated as a slime and Demon Slayer. It has been 250 years ever since rimuru defeated Yuuki, and he has spent 50 years doing paperwork ever since, He feels like passing out. Ciel then suggests that he travels to another universe so that he can satisfy his boredom, Tune in to find out what happens next. Also, Rimuru will get a gender in between the process, he will be a male.