First off, sorry if this is a little oddly worded. I was daydreaming in bed and had a moment of brilliance that I felt I should share before it leaves.

Black Kat Camps are a "curse themed" candlestick keep, and only spawn at random depths (treasure vaults, graveyards) in tiers 2 and 3. These levels are set up mostly like a standard candlestick keep, however the actual level is a little bit brighter (the pathways aren't as dark, but are still dark. In this level, all status based kats are replaced with a new kind of kat - a mini black kat! Mini black kats are similar to standard black kats, however they are the size of normal kats, sound like other kats of their tier (and losing the tweaky aura, but otherwise looking similar to the big black kats), and can only summon 1 zombie at a time. They also have health of the standard kats of their tier.

Now that we have balance out of the way, every variant of this level will have a "nest" room. The nest rooms can be copy-pasted from the black kat prestige mission that ends in a candlestick keep (bad luck and brimstone), but be curse themed. The set black kat spawns are still black kats, not a mini black kat (however there might be several mini black kats fighting alongside the regular black kat). The kats don't drop any ancient pages, and the mini black kats don't either - that is saved for the event.
During the kataclysmic confrontation event, black kats could have a 5% higher spawn chance in these levels(?). This might bring people more motivation to go to the arcade to hunt kats rather than just spam missions for two weeks. When the event is not active, we can still get to fight black kats randomly, even if we don't get an ancient page reward.

The level name could be "Candlestick Keep: Cursed Kat Camp".