I've run the dungeon 4 times with disappointing loot (total 4 gold chests). It's not particularly difficult but there are a few things worth keeping in mind.
- The ninja-mage guys are the only place where there seems to be any real threat since they can confuse or sleep you.
- There's a stage with 3 trap statues, 6 open floor spaces, and then 3 bamboo against the wall. The open spaces are all bear traps. You can heal through it or you can rat bag it, either way it's worth going for the bamboo and hoping for more chests. (This stage doesn't always appear.)
- Boss only has 75HP and so far every time he spent at least 1 round buffing himself (I've seen Brute Force and Falcon), he can hit a few times a round also but he hasn't done much damage at all.
- Disagreeing with the last point, the boss can 3-hit and 4-hit you. When buffed with Brute Force, that can be 36 HP against HQ, and you might not manage the 0-heal. So... use falcon after a few rounds.
Gear used: Legendary Galactic Baton, Warrior Momotaro, Safety Shield/Insomnia Shield (Insomnia seems better so far)
Recommended using Warrior Momotaro + Insomnia Shield or Heck Queen + Safety Shield, 2+ Heal Scroll (3+ if HQ set to compensate for low HP), 0-1 Rat Bag, and maybe throw in a Falcon if you'd like but it probably would get used.
Alternate opinion: With two runs attempted and completed, using LF and HQ+Safety, no heals were needed, and only 1 falcon (at the heno boss). That's uses, not scrolls. So, easy mode. That's without brute-forcing the bear traps (which don't always appear). Worse luck could easily have required a few heals though (or equivalently falcons, with HQ). I'd be comfortable running with one heal (scroll or pot) and one falcon. Two heals if you're not willing to restart a level on bad luck (though I only did that to test the next point). Given the mediocre loot - the only reason to come here is the mask, I think - consider bringing a miracle pot. I did so on my second run. At first, killing the boss got me a silver chest, but restarting the level and immediately using the pot got me a dozen gold bars and silver ores, *and* a platinum chest from the boss that indeed held the mask I wanted.