Is the slime-covered key in Drezen suppose to disapear from inventory?

It disappears when I click on the sword of valor banner. Additionally, when I go back out with the three keys and click on the wall that says, “three hidden key holes” nothing happens.

Yes. If you have the three keys you unlock the last gate before the balor and avoid having to fight the waves that come when you batter it down.

But I found the final “slime-covered key” on the minotaur right before the banner, after the gate and balor.

I think it is key to room optional boss. You can unlock it with Trickery, if you jam it you cannot open it anymore even with key.

You need keys from three Dretches.
They are in

  • Prison (in front of Arueshalae)
  • Tavern
  • Temple (near barbarian with hide armor that dispells buffs when attacker crits)

Ah ok, that makes sense then. I picked that lock and promptly got destroyed, although it didn’t help that 2 characters were trapped outside the door. For me, having a guy or two trapped outside the door happened quite a bit in Drezen citadel.

If they don’t want a LOT of people confused about the keys (being 4 in one area), they could add a description to the three wall keys and the wall. Something like, “3 star shaped keyholes”, “star shaped burnt key”.

There is dialoge for it. Conjurer and Dretch talk about these keys, Dretch even says where they are.