I have managed to find a link to the pdf version of Prima's Ghost Master Guide. This guide has 200+ pages. It includes all of the game mechanics, explains every mission , order, power and even gives more insight into the lore giving ghosts extended bios! Because the book itself is very hard to actually buy, I found the link to the pdf version of it. firedrop.com/63bf8bb71c676827
If possible, I shall try to gather some information from the book and type them up in the thread in order to archive the stuff we did not know yet. If anyone's up for extending the list of things inside the book please feel free to type it up inside the thread.