This story takes place before Rimuru's reincarnation. Shizu, also known as the Conqueror of Flames, responds to an urgent request calling her to the Kingdom of Filtwood. When she reaches the castle, many adventurers are already there. What request could have demanded such a huge gathering? It turns out a demon has been revived, and the adventurers have been called to subjugate it. It is said that more than ten of the most skilled adventurers have already been killed by this demon. But there is more to this request than meets the eye...
Did you know that there 
are ranks among demons?
هل تعلمين أنّ للشياطين رتبة؟
Du weißt es sicher.
Dass es Ränge bei Dämonen gibt.
¿Sabías que hay rangos
entre los entes demoníacos?
¿Sabías que hay rangos
entre los entes demoníacos?
Comme tu le sais, il y a aussi
une élite chez les démons.
Lo sai, vero?
Sabia que há uma hierarquia
entre os demônios?
Ты ведь знаешь,
что и у демонов есть иерархия?