Dungeon Busters ~Chuunen Otoko desu ga Niwa ni Dungeon ga Shutsugen shita node Sekai wo Sukuimasu~ - Vol. 1 Ch. 2

[MangaDex]

 

[Basic_human]

You can't bring weapon from outside. What about construct it inside?

Like bring gun powder ingredients

 

[welcome2atlantis]

Even if he hadn't entered this dungeon, someone somewhere would've done so anyway. If it was inevitable, the more cards you had up your sleeves, the better.

 

[Drifter]

So, if ten years pass and there are still a few dungeons left, the monsters will come outside where we will waste them with overwhelming firepower.