1-11 (8,942 xp) ~ 88 monsters (jelly beans/ pumpkins)
11-21 (68,523) ~ 187 (whoopies)
21-31 (314,420) ~ 365 ( Rackie Hooligans)
31-41 (1,562,370) ~ 1319 (Beetle Fighter)
41-51 (1,903,040) ~ 1166 ( Porkie Hooligan)
51-75 (39,312,464) ~ 6182 (Krawfy)
75-101 (80,606,506) ~ 5612 ( lunaris bear)
101-120 (121,877,268) ~ 7080 (Shaman Ghost)
120-130 (73,903,548) ~ 1985 (Nephenthes)
130-161 (519,593,932) ~ 10,089 (Iron Golem)
161-181 (982,904,654) ~ 18,973 ( Arachnid)
181-220 (4,694,752,875) ~ 77,748 (Desert Scavenger)
220-230 dungeons unknown estimate on spiders killed in CoU, i'm sure someone else can find out if we really want to know.
So in total, ~130,794 mobs just to get to 220 alone. 250,000 doesn't seem so absurd now. More importantly at end game almost all dungeons are mass mob killing anyways, so this large number of mobs required to essentially acquire the book really isn't that bad. Plus farming people do and event farming and one really will not even need to be max for too long before finding it for themselves. I would prefer the book drop straight into someone's inventory like how Hiria's Tear works currently to avoid looting complications. I would have nothing, no in game items, or item mall items help or change the chances of this knowledge being obtained in any way. Only conviction of will from the Visitor determines when they see themselves as part of the larger struggle, and thus are privy to its knowledge.
I know that this seems a little anti-pvp in some aspects but time for a quick honesty cap, so is most of the game. Others have brought up some of its up sides in conversion and amount acquired in games however compared to the valor equivalent. Either way I personally do not know the pvp side of the game very well so I'll leave that side of it to those with the knowledge. I assume the amount of kills would be less in pvp situations so I see no reason why it could not also drop from pvp encounters. Even with people "fixing" pvp situations since the odds are so high and are already from anything anyways pvm is clearly the quickest way to achieve the sheer numbers required here in my opinion.
With such large odd figures here it begs the question of if someone is really really unlucky will they ever find the item? I think most that really play a character will easily see the item but none of the payoff will be game changing in pvm or pvp situations. The reward will be purely ascetic so it is easier to allow it to be more absurd in the acquisition. The one big daunting question left in my mind is do we allow it to be traded or not and I would personally like to lean towards no, requiring it to stay as sort of a thank you for really playing them game essentially. Plus with the odds we are talking about it seems plausible to assume that it will have a big enough effect on the economy that I would just like it to stay out of it.
The whole over-arching theme on this will be about a Visitor's inner self, so I really like the idea of it staying with the one character it is acquired with. Something really notable and memorable to those with true conviction or truly blessed with luck by Aura.