I'm relatively newish (been lurking for quite some time just not much for sharing), but I have read all the Q posts and not once have I seen a typo. When searching the word "Darnkess" (post 97) it leads to a book by Aitken (3 Days of Darkness) on Amazon. Listed with this book is 'Baron Trump's Marvellous Underground Journey' written in 1891 & 1893 by the American author and lawyer Ingersoll Lockwood, which leads to another book, written by the same author in 1896, '1900: Or; The Last President', edited in 2017 by Tarl Warwick. Tarl Warwick has an interesting list of books he has authored dealing with black magic, demonology, and other occult related topics.

Given the information posted by Q, it would appear this is a rabbit hole that was meant to be traversed by the word 'darnkess'.

88: Ten days. Darkness.

97: 10 days. Darnkess. - '10' in digits instead of spelled out like in post 88 resembles the title of the book '3'

Side note: As the title of the thread states and the two posts show - There is no post stating 10 / Ten days 'OF' Darkness / Darnkess.