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...
Even one hailed as a champion 
has no more power than this?!
حتّى النّصيرة لا تمتلك قوّةً أعلى من هذه؟
Das ist also die Kraft,
¡¿Incluso una heroína
no tiene más poder que este?!
¡¿Incluso una heroína
no tiene más poder que este?!
J’aurais cru qu’une héroïne
aurait plus de répondant !
Certo che per essere una di quelli che chiamano Eroi
Mesmo aquela que chamam de campeã
não tem mais poder que isso?!
И это всё, на что способна
даже прославленный Повелитель пламени?