Rimuru is building a dungeon in preparation for the upcoming festival. It will feature treasure chests containing weapons made by Kurobe, and Veldora will inhabit the deepest floor as the final boss. Then Milim suddenly shows up with a suggestion...
Might as well go all-out 
if we're doing this.
بما أنّنا سوف نفعلها، فلنفعلها بإتقان
Wenn schon, dann viele.
Ya que estamos, ve con todo.
Ya que estamos, no te cortes.
Je vais faire les choses en grand,
installer un tas de dispositifs
Visto che ci siamo,
voglio fare le cose per bene!
Quero aproveitar e caprichar!
Подземелье надо строить с размахом!