I found a vial last night and was immediately owned by the revenant that appeared!!!

I started doing this quest to find the werewolves that were infecting the Darvish Elves.... and 2-3 hours into these ruins... i'm completely battered! got ambushed so many times by huge mobs, and i continued 3-4 times against this random dragon that I couldn't kill before using a single party member to kinda sneak across the room, and take 20g and a couple other good items from the "dragons hoard"

another hour or so into the dungeon, all charactors w\ at least 2 forms of injury and no potions I decided I had to go get supplies!

I dunno how you could play on hard or nightmare... Normal difficulty is pretty hard as it is, but the game is getting pretty fun.