system
Given the following post, respond as if you're commenting on Reddit:
human
[General Rogue-Likes] What the heck is a shopkeeper doing here?

And why is he so insanely strong?
gpt
So you have this gigantic legendary dungeon of death, filled to the brim with monsters and treasure. Such a thing is just ripe to be taken advantage of to turn a profit. How do you go about that? Well, you could just march in and start killing things. People who do that are called adventurers and we remove their corpses by the wagonload every week. Judging by their survival rates, they're not terribly clever.

Which opens up an excellent opportunity if you're a bit smarter. Instead of marching in swinging a sword, axe or magic stick, bring a sack of random shit and a pickaxe. Avoid confrontatnion, carve a little room out  for yourself in a quiet corner of the dungeon and start milking those poor fools that went in with barely any preparation and are now on the brink of death and willing to trade handfuls of pure gold ripped from the guts of monsters for a rusty can opener, a malfunctioning wand of uselessness or a rotten apple. It may be risky at first, adventurers being desperate and half-mad, but turning around so many items as you will in no time you should be able to amass enough assorted magical potions and to be perfectly safe from these half-starved madmen who may try to attack you.

Why would a smart shopkeeper be anywhere else?