Seems that at least me and Astral have "found" this challenge on our own.
The challenge goes like this - you go in with a vicious token whenever the PQI sends you there, and you must only get the VT and the badge you're supposed to get and fail all the others.
This is trickier than it sounds!
The only way to fail unstoppable (that I know of) is to bring in a Titan's Guitar, which then means that most often you're playing a cramped VT run without a major item. Then you have to also leave one of the lvl 7 guys alive, which means you're playing VT without a lvl7 guy. You also have to fail efficiency by forgoing Cheeky, etc.
But you're also supposed to do whatever badge you're supposed to do, except you're doing it on a restrictive VT run wheve you didn't choose your race. Hoarder can get tricky if you pick stuff off the floor. Ding! Max without Unstoppable? It's a nice little puzzle, not the hardest but sometimes quite devilish.
The only problem is that it can't be done purist (unless you scum for a guitar), and can't think of a way to fail specialist if I'm going warmonger.
So I was thinking - what about Vicious Hobblers having special rules? Like an item that lets you somehow fail Specialist on Warmonger or some way to enable Purist to still fail Unstoppable? You can't take anything out of there anyway, so an item seems ok, but the Unstoppable enabler shouldn't let you get Unstoppable without the Guitar or make it a guaranteed badge.
Anyway, just a thought. The challenge makes for a strange alternative way to play, and a nice way to make Vicious Hobbler a legit dungeon which could even let you get money. Also potential flavor about "Hobbler deciding that being the punching bag was beneath the famous architect and proposing a proper challenge to the kingdom".