~1.24% chance for a Black Kat to spawn in any Kat
~1.02% chance of a Book of Dark Rituals dropping from any Black Kat
~32.1% chance of Black Kat spawning per run
~0.29% chance of Book of Dark Rituals dropping per run.

~94.26% chance of guaranteed Book of Dark Rituals after approximately 300 runs or 100 Black Kats.

I know ppl with even worse luck with the book, but I just found my first after about 940 kats. The probability of that is insanely low. Assuming it's 1% the likelihood of killing 940 kats without getting a book is about 0.008%. I believe the drop rate is lower than before whiskers were added, but most of the kats I've killed were during earlier events.

Also, spending 200k on rolling is nothing. You shouldn't expect to get anything good for it. Here's a a pretty good page if you want to know the expected costs of different UVs: http://wiki.spiralknights.com/User:Jdavis/UVs

"You had successfully made me more depressed and sad
Can anyone find my hope back?"

Here's a gif of a puppy trying to eat an ice cube. I hope it helps <3
You can watch it while listening to Eye of the Tiger.

Started the event with around 1248 ancient pages.
Since I have pretty much no life that number is now 1,744, however I spent 50 on a fetish, bringing my farmed value up to 1794.
So far I have made 546 ancient pages this event.

Now if we take into account the daily prestiges, that is about 24 pages not from black kats. This means I have encountered roughly 174 randomly-spawning black kats this event.
Assuming black kats are spawning in once every four runs, I have run through at least 696 candlestick keeps (outside of one black kat I found in legion of almire - that was interesting)
No book has dropped for me this event so far, but statistically, should soon.

For all y'all calling it quits after like, 20 runs, that's why you don't have a book. Now in the past I've gotten 3 books of dark rituals total, and statistically I should find one soon, but statistics take an average, so you've got people who find a book on their second run (still jelly of you machi), and you've got people who have never had a book after 3000 runs.

Still waiting on one of these wonderful ideas to make it into the game. This is the only event I can actually classify as "anti-fun", despite me enjoying myself for the duration of these events regardless - but that's because I'm incredibly boring. Not many people are like me in that I find mindless tasks that make a number go up satisfying - most people find that mind-numbingly boring, repetitive, and unfun.

For sure killing 200 kats won't net me a book of dark rituals. I understand how the system works, but assuming that it's a 0.5% chance of a book, that's a 1/200 chance for a book.

Post context is pretty heavy there. I go on to say that it can be one kat for a book or several thousand and still no book. Doesn't change statistics, but statistics aren't a progress bar, despite this event heavily needing to have a progress bar to be worthwhile.

I found the book after about 4-5 cats.....