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...
You call it "unrivaled strength" just 
because they can kill a mere lesser demon?
أتسمّيها "قوّة لا نظير لها" فقط لأنّهم يستطيعون
قتل مجرّد شيطان أدنى؟
¿Lo son solo porque pueden
matar simples Demonios Menores?
¿Lo son solo porque pueden
matar simples Lesser Demon?
Ils étaient seulement possédés
par des démons mineurs !
Sarebbe impareggiabile perché riescono
a uccidere un misero Diavolo minore?
Chama de força inigualável só porque
matam meros demônios inferiores?
В них всего лишь вселились низшие демоны,
какие они «непобедимые»?