I was rubbing along pretty well in House Of Necrosis before I hurled a vial of unidentified black serum at a squashy purple Devourer. I was hoping the serum would be some kind of poison - I mean, come on, an unidentified black serum? You wouldn't pour that on your chips. It turned out to be an XP potion, which transformed the Devourer into a Foul Devourer - still squashy, still purple, but with much sturdier defence.
I managed to recover some of the accidentally donated XP by lobbing a cheeky hex, but not enough to boost the stopping power of my homely pawnshop knife and pistol. So down I went in a pool of that special red serum the billionaires like to drink when they're feeling mortal.